My BMW m3 was driven by the dealer with no oil for a short period of time, what damage could have been caused?

It runs fine, it has oil in it now. The check engine light cam on for no oil pressure, it was a cam timing code. One of the techs fucked up and drove it with no oil in it between buildings at the dealership. Is there enough oil in the engine after draining it to properly lubricate it for that amount of time. Any advice from BMW techs or people who know their stuff would be much appreciated for piece of mind via /r/cars http://ift.tt/2sagSqQ