The Art of the T

[slow whistle]

Just wanted to get thoughts on administration of technical fouls. Partner calls a foul on A1 from L. As he comes around to report I am T just walking in on the play and she gives him the "wave off" as he walks away. This after the play before where same partner calls a travel on same player who made it clear that she did not agree with that call either. So I whack her for the gesture...my question is though when is the best time to call this? I whistled and gave it to her right away, but my partner turned and had sort of the deer in the headlights look like what is going on?? Fortunately he remembered what he was reporting and we end up administering ok, but are you better served in this situation to let him report the foul and then whistle and assess the tech even if there is a delay from the time that she gives the gesture to when I assess the tech?