Here are movie special effects artists who have given their assessment of the Patterson/Gimlin Film
Rick Baker. Famed Hollywood creator of Harry (from the movie, Harry and the Hendersons), Rick Baker, told Geraldo Rivera's "Now It Can Be Told" show (in 1992) that "it looked like cheap, fake fur," after seeing the subject in Patterson's filmstrip. Baker said that John Chambers had "a crappy walkaround suit," that he sold as "a gag to be played on the guy that shot it [the film]". Later on, Baker's studio stated in a fax, "He no longer believes this [that Chambers made the suit] is true."
Ellis Burman. The Guenettes (Robert & Frances) wrote of him, "I also spoke to Ellis Burman of Burman Studios in Hollywood, creators of all kinds of strange creatures, including a fake Bigfoot for a traveling 'pickle and punk' carnival exhibit. Burman denied his company created the Patterson Bigfoot, but did say he could duplicate it—but for more than $10,000 in total costs."
John Chambers. Academy Award–winning monster-maker John Chambers is most famous for his innovative flexible masks in Planet of the Apes (1968). In a 1997 interview in a nursing home with Bigfooter Bobbie Short in her nurse's uniform, he denied rumors that he had created a costume for the Patterson subject, saying "I'm good, but not that good."
Some time before 1976 the Guenettes reported that, in answer to their questions, "He concluded that if the creature is a man in a suit, then it is no ordinary gorilla suit. It is not something they bought or rented in a store; it would have to be something tailor made. He also felt like it might have been made out of real animal fur."
Janos Prohaska. After viewing the Patterson–Gimlin film with John Green, costume designer and ape-suit mime Janos Prohaska (noted for his work in the late-1960s television programs Star Trek and Lost in Space) concluded the film's subject looked real to him. When asked if he thought the film was faked, Prohaska replied, "I don't think so ... to me it looks very, very real." If the film was hoaxed, Prohaska thought, it was remarkably realistic and sophisticated, and the best costume he had ever seen, and the only plausible explanation was that someone might have glued false hair "directly to the actor's skin".
However, film critic David Daegling speculates that the same effect could be had by gluing the hair to a set of tight but expandable, waffle-design long johns.
Chris Walas. Academy Award-winning "makeup artist Chris Walas in the BigfootForums (in 2004) presented a theory that the arching hip line represents the overlap line between a fur costume leggings section and the torso section . . . ."
Stan Winston. Academy Award-winning film special effects supervisor and makeup artist Stan Winston, after viewing the PGF, said "it's a guy in a bad hair suit, sorry!" He also added that "if one of my colleagues created this for a movie, he would be out of business." He went on to comment that the suit in the film could have been made today for "a couple hundred dollars" or "under a thousand, in that day".
"Barry Keith" (pen name), "an experienced make-up and costume artist," accused "the Hollywood costume industry" of making "bravado claims of how easy such an event would be to fake". He said that their "cheats and shortcuts" are not detectable in "Patty".
Disney executive Ken Peterson. Krantz reports that in 1969, John Green (who owned a first-generation copy of the original Patterson film) interviewed Disney executive Ken Peterson, who, after viewing the Patterson film, asserted "that their technicians would not be able to duplicate the film". Krantz argues that if Disney personnel were unable to duplicate the film, there is little likelihood that Patterson could have done so. Greg Long writes, "Byrne cited his trip to Walt Disney studios in 1972, where Disney's chief of animation and four assistants viewed Patterson's footage and praised it as a beautiful piece of work although, they said, it must have been shot in a studio. When Byrne told them it had been shot in the woods of Northern California, 'They shook their heads and walked away.'"
Dale Sheets and Universal Studios. Patterson, Gimlin, and DeAtley screened the film for Dale Sheets, head of the Documentary Film Department, and unnamed technicians "in the special effects department at Universal Studios in Hollywood ... Their conclusion was: 'We could try (faking it), but we would have to create a completely new system of artificial muscles and find an actor who could be trained to walk like that. It might be done, but we would have to say that it would be almost impossible.'" A more moderate version of their opinion was, "if it is [a man in an ape suit], it's a very good one—a job that would take a lot of time and money to produce."
Jeffrey Meldrum of Idaho State University cites efforts by John Green as important in his own studies of the Patterson film. "It has been obvious to even the casual viewer that the film subject possesses arms that are disproportionately long for its stature." Meldrum writes that "Anthropologists typically express limb proportions as an intermembral index (IM)" and notes that humans have an average IM index of 72, gorillas an average IM index of 117 and chimpanzees an average IM index of 106.
In determining an IM index for the figure in the Patterson film, Meldrum concludes the figure has "an IM index somewhere between 80 and 90, intermediate between humans and African apes. In spite of the imprecision of this preliminary estimate, it is well beyond the mean for humans and effectively rules out a man-in-a-suit explanation for the Patterson–Gimlin film without invoking an elaborate, if not inconceivable, prosthetic contrivance to account for the appropriate positions and actions of wrist and elbow and finger flexion visible on the film. This point deserves further examination and may well rule out the probability of hoaxing."
In his book, Meldrum says, "[Reuben] Steindorf tracked the joint centers through 116 frames of the film, yielding a reliable estimate of the film subject's limb proportions. ... The combination of these proportions with the exceptional breadth dimensions argue[s] compellingly against the simplistic hypothesis of an average man, even one wearing shoulder pads ... or using artificial arm extensions."
Anthropologist Grover Krantz was originally skeptical of the Patterson film, based on the still photos in Argosy Magazine, but changed his mind in 1969 after seeing the film because "the realism of the creature's locomotion impressed him." He later offered an in-depth examination of the Patterson film. He concluded that the film depicts a genuine unknown creature. Primarily, Krantz's argument is based on a detailed analysis of the figure's stride, center of gravity, and biomechanics. Krantz argues that the creature's leg and foot motions are quite different from a human's and could not have been duplicated by a person wearing a gorilla suit. Krantz wrote, "the knee is regularly bent more than 90°, while the human leg bends less than 70°." Daniel Perez brought out the implication of this, writing, "The subject['s] ... toes lift off the soil at least ten inches in every walking cycle. ... René Dahinden ... filmed and studied how modern man walks, finding ... a maximum of 2–3 inches of distance between toes and the surface it is walking over . . . ." No human has yet replicated this 10"-high lower leg lift while maintaining the smoothness, posture, and stride length (41") of the creature.
Krantz pointed out the tremendous width of the creature's shoulders, which (after deducting 1" for hair) he estimated at 28.2 inches, or 35.1% of its full standing height of 78", or a higher percentage of its 72" "walking height," which was a bit stooped, crouched, and sunk into the sand. The creature's shoulders are almost 50% wider than the human mean. (For comparison, André the Giant had a typical human ratio of 24%. Wide-shouldered Bob Heironimus (see below) has 27.4%. Only very rarely do humans have a shoulder breadth of 30%.) Krantz argued that a suited person could not mimic this breadth and still have the naturalistic hand and arm motions present on the film.
Krantz and others have noted natural-looking musculature visible as the creature moved, arguing this would be highly difficult or impossible to fake. Hunter and Dahinden also note that "the bottom of the figure's head seems to become part of the heavy back and shoulder muscles... [and] the muscles of the buttocks were distinct."