i think public safeyt must come first, whether its an escaped prisoner or zoo animal.
i would guage the threat level of a chimpanzee male as being as high as an escaped bear, big cat or rampaging elephant.
interestingly, i thought it would be a matter of time before these animals escaped. im just about to read the article, but as anyone who has seen the enclosure design could tell you, the back fence only extends out over the moat by about 2 ft or so, with hotwires preventing access.
i thought it was quite a brave way to contain the animals