Sorry to say, but you have no idea what you are talking about ... and sadly not the slightest idea of how "no animation" looks like ...
it can be the case, that due to your shitty pc specs or cause you didnt have him in target or have been tabbed out of the game, the animation isn´t displayed correctly, but he isn´t using anything else in the meantime ... the dmg numbers show that btw. And the Ripclaw is 100% legit animated^^. If you don´t think so, read my sentence above ^^
Overall 5 seconds to kill somebody 100-0 with those dmg numbers is legit in my opinion.
In my eyes he is a legit player.