Heck! I think it might have been easy for him to get out from there if he had wanted to ?
It reminds me of when Jambo first arrived and was let out into the outdoor enclosure(now the Chough Aviary much modified). Apparently he leapt from the climbing equipment onto the perimeter wall but fortunately jumped back in(rather than out) again. They quickly cut down the size of the climbing frame so he couldn't repeat it! (Taken from Richard J-Scott's book on 'Jambo')
