Well, there is a bug in the AMX player initialization code when there are bots at the server. After a few player connects/disconnects AMX doesn't update it's internal tables therefore it mix up players. That's also the reason why the wrong player get's punished...
I suggest you disable the AMX tkpunish and use either mp_tkpunish or the ATAC plugin. The later is also influenced by the AMX bug but requires the players to choose a punishement. But after some teamkills (default 5) they are kicked anyway
