Dmaker,
Using, for the sake of argument, the example of the prolonged, unobstructed viewing of an animal moving swiftly through difficult terrain (deep snow covered by ice) that slows humans down to a slog, and which ends with the animal that looks a lot like a large, upright primate w/in spittin' distance of the witness - who has a weapon, but rationally decides that, "nope, I need a bigger weapon and I'm not gonna' shoot this thing and tick it off" - leaves us with the following possibilities:
The person saw a large, upright ape - it's possible
Misidentification - seems to be ruled out by the prolonged, and ultimately close-up, viewing of the
critter
Hoax (played on an unsuspecting victim) - seems to be ruled out by the difficult terrain that limits a human's ability to run
rapidly and the relatively poor decision of pulling a hoax on a person armed
with a weapon (and who is not in on the hoax)
Hallucination (an unknowing falsehood) - I'm not a psychologist but that's either a heckuva hallucination or I want some
of what he's smoking; I'll grant that its possible for a limited number of people
to experience such explicit hallucinations w/o realizing that its not real, but I it
seems unlikely that there are enough such individuals to account for the
numerous reports
Hoax (by perpetrator) or flat out lie - I'm sure that there are reports/"evidence" that are knowing and deliberate lies
(or knowing and deliberate decisions to ignore the more plausible explanation,
i.e., an elk wallow held out as bigfoot eating fruit Roman style) but....
Lies are easy to tell the first time but difficult to maintain. I would love for a psychologist who has clinical experience (and the requisite knowledge of professional studies) to weigh in on this as I only have anectdotal information, old age, and experience to draw on. I would probably end up typing for an hour (or more), but I'll just leave it at two points. First, its equally illogical to dismiss an account as a lie, without more, as it is to accept every account as truthful, without more. Second, the easiest lie to get away with is a simple lie told by a single person. When a lot of people are trying to tell a lie to support each other's lies (w/o coordinating their stories), the lie has to revolve around the easiest points to remember & synchronize. While I'm new to this particular rodeo (bigfootery), that's not what appears to be happening.
Don't expect to convert you, but I'll put out that there's probable cause that bigfoot exists - that is, a reasonable man, considering all the available evidence, could conclude that bigfoot exists. Another reasonable man, considering the same evidence, might conclude differently, but that does not necessarily mean that either has made an objectively wrong decision with the information available at that time....
Cheers,
(edited twice to try and clean up the columns and make it readable)