Also, due to desync and client sided shit, u cant really tell someone is hacking, often its just very very unlucky.
Like on the screen of the guy, u are close, but on ur screen, u are more far, u will get hit anyway.
U feel like u hit him in the head cuz u saw blood there? Aint worth a shit, u have to listen to the scream, if he scream a sifferent way( just pay attention, try it out) it was a head hit, or if he dont have a helmet, he should be dead if u got a steel weapon.
If someone onehit everyone, without chopping ther heads, then its prolly a hack xD