The predator stamina system seems stupidly tied to health.
When you have low health it seems like you need to have more stamina in order to leap (or you just have less stamina)
It also regenerates at a pitiful rate meaning leaping is pretty much out of the question especially if you have done ANY sprinting,
So just at the time when you need the stamina the most to get away and save your skin, it is actually removed.

