The final decision was 100 % correct. Well done by the refs (I cannot say anything about the match in general, though).
"For the throw-off at the start of each half (incl. any period of overtime), all players must be in their own half of the court.
However, for the throw-off after a goal has been scored, the opponents of the thrower are allowed to be in both halves of the court.
In both cases, however, the opponents must be at least 3 metres away from the player taking the throw-off (15:4, 15:9, 8:7c)."
and:
"if during the last 30 seconds of a game the ball is out of play, and a player or team official prevents or delays the execution of a throw for the opponents, in order to prevent them from being able to take a shot on goal or to obtain a clear scoring chance, the guilty player / official is to be disqualified and a 7m throw is to be granted to the opponents. It applies to any type of interference (e.g., with only limited physical action, interfering with the execution of a throw such as intercepting a pass, interference with the reception of the ball, not releasing the ball)."