Well the movie starts with a lie.
Relating the story of the initial Washington State incident of 1947, the narrator "quotes" the pilot saying he had seen saucers. Not true at all. And if they start with such a basic and easily disproved distortion, how seriously can you take any of the rest?
""In a memoir of the incident for the First International UFO Congress in 1977 Arnold revealed the flying saucer label arose because of a "great deal of misunderstanding" on the part of the reporter who wrote the story up for the United Press.
Bill Bequette asked him how the objects flew and Arnold answered that, "Well, they flew erratic, like a saucer if you skip it across the water." The intent of the metaphor was to describe the motion of the objects not their shape. Arnold stated the objects "were not circular.""
This is what Arnold described:
http://files.abovetopsecret.com/images/member/c60ac02e4e80.jpg
Comparing this to other experimental aircraft known to exist in this general time frame:
The wartime German Horten HO 229
http://2.bp.blogspot.com/_kujDS7zCRBY/TT4ako3GS4I/AAAAAAAABEE/hDZ-yUhi 55A/s1600/Horton229V1prototypeg.jpg
The American Northrop N9
http://www.kbvp.com/sites/default/files/images/Northrop%20N9MB%20Flyin g%20Wing%20flys%20at%20Chino%202010.preview.JPG