Anything I've seen written about Gimlin rate him as an honest person, even if opinions about Patterson display some misgivings. lately he has been interiewed as a "bigfoot expert" something I don't think he originally claimed to be. Maybe as he's getting on a bit, being offered money to be interviewed as an expert is attractive but he isn't that comfortable with it?
I've not heard of any horseback expeditions and the point that the horse smell masks the human smell may be important. If thir sense of smell is highly developed then the scent of humans or artefacts left by them may be enough to warn them off. Leaping about the forest, shining torches, yelping and banging on trees may well be the best way not to see a bigfoot.