One of my club's experienced IDPA shooters managed that same trick, while reholstering after loading for a stage. (At least he had the good grace to have his oops elsewhere, and not at our local club! )
We always remind out shooters---you may draw on the clock, but you don't holster on the clock. That's true about most holstering situations, too. It's always worth taking the time to do it right.