I think a TV timeout is charged to one of the teams...I forgot which one has to call first, the home or away team.
I'm doing research right now.
EDIT: Ahh..yes.
SOURCE
NBA Rules wrote:d. There must be two 100-second timeouts in the first and third periods and three 100-second timeouts in the second and fourth periods. If neither team has taken a timeout prior to 5:59 of the first or third period, it shall be mandatory for the Official Scorer to take it at the first dead ball and charge it to the home team. If no subsequent timeouts are taken prior to 2:59, it shall be mandatory for the Official Scorer to take it and charge it to the team not previously charged. If neither team has taken a timeout prior to 8:59 of the second or fourth period, a mandatory timeout will be called by the Official Scorer and charged to neither team. If there are no subsequent timeouts taken prior to 5:59, it shall be mandatory for the Official Scorer to take it at the first dead ball and charge it to the home team. If no subsequent timeouts are taken prior to 2:59, it shall be mandatory for the Official Scorer to take it and charge it to the team not previously charged. The Official Scorer shall notify a team when it has been charged with a mandatory timeout. Any additional timeouts in a period beyond those which are mandatory shall be 60 seconds. No regular or mandatory timeout shall be granted to the defensive team during an official's suspension-of-play for (1) a delay-of-game warning, (2) retrieving an errant ball, (3) an inadvertent whistle, or (4) any other unusual circumstance.
So basically if a timeout has not been called before 5:59, it is charged to the home team. And then at 2:59, if a timeout has not been called before then, the team that was not charged with the timeout earlier is now charged.