Iowa was in the double bonus, so it would've been 2 FT's. And if both were missed, UNC would've had to go the length of the court anyway. Make either, and it's a moot point with a 4 point lead. A better FT shooter than Woody would've been a good thing of course, but in the end, it didn't matter.
I wonder if Woody didn't just react and call TO to secure possession more than anything else, rather than a case of his thinking "I can call timeout and we'll have the chance to inbound to a better FT shooter". Who knows, but that seems like rather quick thinking to make on the spot like that.