Delay After Halftime

[mj]

Watching a game this weekend where this happened. Team A is not out on the court when the halftime horn sounds. The possession arrow is Team A.

Should the ball have been put down and the throw-in count start for Team A? If so, then Team B gets the next throw-in? Then it's a technical foul on Team A for delay? Correct?

BTW, the official in this game waited for Team A to come onto the court. I believe he told Team B's coach that he waited because no one properly notified them at 3 minutes.

Thanks,
MJ