Not only can a technical foul be assessed, it should be assessed....
Direct from the Case Book... (see the "comment")
9.2.10 SITUATION A:
A1 is out of bounds for a throw-in. B1 reaches through the boundary plane and knocks the ball out of A1’s hands. Team B has not been warned previously for a throw-in plane infraction.
RULING:
B1 is charged with a technical foul and it also results in the official having a team warning recorded and reported to the head coach.
COMMENT:
In situations with the clock running and five or less seconds left in the game, a throw-in plane violation or interfering with the ball following a goal should be ignored if its only purpose is to stop the clock. However, if the tactic in any way interferes with the thrower’s efforts to make a throw-in, a technical foul for delay shall be called even though no previous warning had been issued. In this situation, if the official stopped the clock and issued a team warning, it would allow the team to benefit from the tactic