i am pretty sure that the gorilla doenst want to to anything but he is very stressed, i think when they used something like a narcoses. he get even more stressed and he can hit the kid when they shoot the narcoses.
also i cant judgement about the parents are bad, cause 2 reasons. 1 i dont know them 2. i am a parent, and as parent i know fast they are and every parent ever lost there child for a second, and within the second much things can happen.
think this story only got losers.
and the only think is what i ask myself. how can a child even fall/climb into the habit of the gorilla