An environmental puzzle boss fight. They can be quite annoying if not designed well. Here it seemed quite good because Leon didn't have much weaponry in the first place, so it was clear he couldn't simply kill the zombie lion directly. I have played games where the boss just has unlimited HP and the player a whole lot of weapons, but all the attacks and effort will be wasted, until you trigger the scripted event to destroy the boss. Those can be somewhat annoying, although sometimes you still need the weapons to take out ordinary enemies appearing here and there during the boss fight.