Some FBS conferences want an announcement. Making an announcement isn't necessarily mandatory, but it does at least two positive things: 1) It reinforces the rule by making everyone aware of the violation and the violator, and 2) it lets the media (TV talking heads, in particular) know what's going on so they can sound smart by talking about the new rule. Since the clock is stopped, it takes nothing away from the game to make the quick announcement. The crew can record the number, to make sure he doesn't try to return.
Saw it happen three times Thursday night, with an announcement made each time. Smooth as glass. With luck, the frequency will decline dramatically, and the occasional announcement won't disrupt the game to any significance.