You state you had it running 30 minutes for a quick 4 minute drive, so you let it warm up for 26 minutes at idle? How long after that drive did the restart attempt happen?
My suspicions centre around the car then on restart being warm, and drawing in colder intake air, giving the computer a bit of a shock as it was expecting 'nice warm under the hood' air. The open loop program would have been upset at that point, and caused it to take a few extra rotations to recalculate for the rapidly changing temperature variables, and find a fuel ratio that would work for the new temp. Just speculation, but it is a possibility. Hopefully this is an isolated incident.