Currently, if you run out of time in deck construction in a draft or sealed it does something along the lines of piling all your cards into a deck and making you play with that. This is an annoying feature that has caught me twice when, for various reasons, I was planning on committing my deck until the very end. In each case I actually had a legal deck in the upper area. In both cases you get such a random, base heavy set of cards I might as well have conceded turn 1. I could also imagine this being a problem if you disconnect late in the deck building process.

A much more user friendly action when you run out of time is to set as the deck whatever was in the upper area. If that wasn't a legal deck, you can add random cards from the set until it is.