A lot of skepticism is in order with anything Koko. No skeptical scientists have been allowed to 'communicate' with Koko. Thus only believers, people who are willing to provide very generous interpretations of the ape's behavior are allowed to work with her.
I think only a believer would get so physically close to such an animal. She isn't a person, nor a pet. I can understand her keepers not wanting unfamiliar people around if they might upset her. Or she, like humans, may not display the same behavior around strangers.
The Gorilla Foundation has no problem granting access to celebrities (e.g. Robin Williams) or the media. Critical behaviorists or linguists have had no such luck in access. In the videos I have seen the trainer acts like a tarot reader: Koko will make a bunch of signs/movements and then the trainer will interpret for you what it means. So long as you want to believe it all makes sense.
