Interesting story. I believe it happened as he describes, and what it was remains a question. But to go from "great ape" sounding noises to "Big Foot," I don't think so (Les does not make this jump). I keep an open mind, but I am skeptical and need really hard evidence.
I just think that you can never go from "I don't know what that was" to "it was Big Foot, a UFO, a ghost etc. etc etc" The logic just doesn't work for me.