That is an interesting choice of containment for a leopard.
At Great Cats World Park (Oregon, USA), I saw jaguars, an Amur leopard, a Geoffrey's cat and an African wildcat climb part of the way up chain-link fencing. See below:
I don't know every law in every US state but I kknow that this would not fly in Florida, where keeping any cat except for lions tigers on open top enclosures.
@Shirokuma That's obviously true from the photos. It would be interesting to see if a leopard at Parc Zoo du Reynou would ever be inclined to climb up the fence in order to catch a bird or perhaps show an inclination to escape.
It was never reported but a leopard escape could have arrived in my opinion. From my personnal experience, I saw guereza colobus escaped from their island and playing near childs. I found a keeper but he looked not really concerned by the problem. He told me that it arrived quite often !