No, I am talking about booting someone from a battle.
On PS2, there is no chat function, either in the "lobby" where you choose servers, or in the game itself.
You're very right that booting became a huge problem in JA/JK2. But at least the issue could be somewhat discussed by the whole room. And it came up mostly in Free For All rooms.
On the PS2, there is no discussion, and half the room (i.e. - the other team) is usually unaware and unaffected by the team killing that is going on. They may see the message at bottom "X killed teammate Y", but unless they see them repeatedly, they will probably dismiss it as friendly fire accidents. And even on the post-battle stats board, you have to scroll down to the bottom to see the stats for TK'ers, since their score is always negative.
The only way the situations becomes apparent is when you see the message "Boot Player X, 1 yes, 59 sec". After a while, more people are team killed or understand the message, but in the course of a battle, momentum rarely builds up past four or five votes. And a TK'er can prevent his booting by repeatedly calling a vote on booting another player. The system sucks right now.
It would be best if voting was handled by teams. And it would be nice is there was a quicker way to vote that wasn't guaranteed to get you killed if you are anywhere near the front. Unless we get admins in PS2 battles, that seems like the only workable way.