Exactly this. Since he stated he had a queue, that basically means he was a dps. My guess he was pulling and being an idiot, or purposefully bursting the first 3 seconds to give the tank a headache.
I tank heroic dungeon pugs constantly.. and I can tell you from experience, the biggest headaches and causes of wipes are people with great gear. Not only do they make things harder on the tank, they makes things longer.