gorillas are individuals. the way they will react to different situations depends on their personality, which is in turn a function of their life experiences.
think of it like this. let's say the situation was flipped and a gorilla fell into the human pit. would you say "humans aren't dangerous, it's fine."? that would be an error, wouldn't it? many humans would bludgeon the gorilla almost immediately. but, it would be no less of an error than saying "humans are vicious monsters, shoot it!" - as plenty of humans would take the time to care for the child. put tersely, you would shoot if it was jeffrey dahmer in the enclosure and shrug if it was mahatmas gandhi. right?
while you can probably be pretty sure that the male gorilla in ohio would not have eaten the child, as a distant onlooker you and i are simply not qualified to say anything else of any value. in order to make a worthwhile decision, you need to be familiar with the personality of the animal.
this is a situation where experts are experts because they are experts, and everybody else is not because they aren't.
https://www.youtube.com/watch?v=8Xr1YjwDNm4