Is it normal that Graves get a e after every normal attack?

I recently had a game and the Graves in the opposite side can use e after every normal attack(started at very beginning of the game and that works on minions) and just jumps around like a freaking kalista. when we asked about that, he said it was about "e animation cancel", so is that normal to the game, or is that a bug, or maybe hacked? I am really curiosed about this