It is supposed to be a reflection of past betrayals, but if it is, it's highly flawed.
Just the other day a guy betrayed me FOUR times before I could boot him!!!
I find it hard to believe that he "all of a sudden" decided it would be funny to betray teammates, and that it was something that he rarely does.
On the flip side I NEVER purposely betray, yet when one of my stray 'nades kills a teammate I get booted?!
It should ALWAYS give you the option to boot the second time someone betrays anyone twice in a game.
Accidents happen, twice in a row is a pattern.