Odd, I didn't see any log of him TAing even once, much less 5 times.
What other plugins do you run that may be causing people to die by "world" or some other form of suicide? If I recall correctly, unless properly coded, some plugins that cause a player to die could, my omission, attribute the death to a player that has previously attacked the one dying. Also, any plugins that would switch a player from one team to the other?