It's interesting, but having 6 toes is not really proof of anything, or of being non-human. Humans do occasionally have 6 toes, and there are even domestic cats that have more toes than they should, and are called polydactyls. So, I think like that may happen in any species from time to time.
I remember the thalidomide babies born to human mothers, and these babies had flippers for arms... the result of a drug messing with the genetic process during pregnancy. It didn't make the babies less than human. It is simply a genetic accident that I really can't explain myself, and I am not sure science has all the answers, but I know that they tied it to thalidomide at the time it occurred. This happened in a number of cases. I am sure the information is in several places on the web.
The "Bugs" situation makes an interesting story, but I think these hunters should have stopped with killing only the first one, (which could rightfully be ruled an accident if it looked bear-like), and calling in the authorities and scientific experts to attempt to discover exactly what this was. The second one should have been left alive, for possible capture and study.
After the lapse of time, how sure is "Bugs" that he still accurately can describe where they buried the corpses? Will they indeed be found? I do hope that the scientific community will then at least get involved enough to find out if they can extract some DNA from these bones. That would clear up the mystery, and we might learn some new things about bigfoot, if this is what these creatures were.