They are given “suggested guidelines”. There is no hard fast requirement to have the enclosure x feet high. They’ve had this exhibit for YEARS and when people don’t taunt them, all is fine. Even kindergartners see this exhibit and don’t get attacked ... .
See 98.
How can you possibly argue the fact the wall was too low? It takes no great leap of logic to understand that if the Tiger cleared the fence, for WHATEVER reason, the fence was not high enough. The height of the retaining structure needs to be based on the animals ability to clear it UNDER ANY CIRCUMSTANCES, including taunting, thunder or whatever else may set the animal off.