Elephants Just Passed a Classic Psychology Test – With More Restraint Than Many Humans
(www.sciencealert.com)
So they made it appear that the path of least resistance was directly in, and then when it wasn't, the elephants realized that there might be a different path of least resistance, possibly similar to the black boxes they'd already experienced? That doesn't sound like inhibition to me.
Exploring the inside of the clear box before taking the fruit may only demonstrate that the elephants rank knowledge of an unknown object higher than consuming a known fruit. Neat, but also not inhibition.