Yea, the sniper isn't perfectly synced in SAMP, so you can sometimes encounter bugs like this. The problem is that it just shows up as 'a shot', but the server doesn't know where or from who it comes from, so it appears he got damaged by a player that doesn't exist (and that's why it gets through the anti teamshoot). Unfortunately there's not much I can do to fix this, so if you encounter this, report it to an admin or try reconnecting, that might help.
