I've done it once.

I had just T'd up A1, and A2 (captain of the intramural team) came up to me to discuss the call. As I pointed for him to just walk away (i.e., I wasn't going to discuss the call), he contacted my arms and I immediately reacted by assessing a flagrant T and giving the "door point" signal.

As soon as I called it, I had doubt as to what exactly had happened (probably a good lesson in there about taking an extra half-second before calling a T), so I discussed the play with the scorer. She had a better view than I did and said that I had actually caused the contact more than A2. I brought both captains together, explained what had happened, and we continued the game with only the T on A1.