Cats attack from behind most of the time. I doubt you would be able to shoot or spray it before he was on you. Still, I would no doubt carry a sidearm. Most of the time human attacks are from hungry juveniles . I won't get into the story by I can attest to how quick a Mtn. Lion will be on your back with its jaws on your neck. An adult lion is stronger than an average man. No doubt here.
Pack a pistol .