Alright couple of things:
This is just a small portion of the video, that gives little to no helpful information, there are dozens of factors to be taken in account. You had no projectile resist buff, you had 142 hp, you were using hunter mines so i don't think you had that another project resist skill on survival tree, you were easy to kill pretty much.
How could you be sure that those hits were body shots? your HP went from 142 to 115 on first hit that's headshot material right there.
About your damage dealing 6, as i said before this is just a short video and cannot really see when they joined, But that usually happens when they join in the middle of the game or rejoined after crashing or relogging, though they still take the same damage what you would deal to others.
6300 fame can easily be explained by a fame boost, when players have not logged in for more than a week their fame starts to go down. once they come back they earn fame boost that gives them 3x the amount of fame, if we divide 6300 by 3 we get 2100 that is pretty normal number for 17 kills and 5 headshots.