this happens to me all the time it is just most likely the person who hit you, (but the proof of the video shows that the person is hacking) there hits did not register with the server yet until later in the game.
but hacks are still alive for robocraft. I was in a game and 1 of my team members had the infinite nano range hack and could heal through walls. but thanks to him my team one ;p.
but the proof of the video shows that the person is hacking.