Is the boat head to wind, or just have the sheets blown?
Luffing doesn't negate the fact they're on starboard and the overtaking boat must keep clear. Luffing at a start is an easy way to hold your spot in a competative OD fleet and used quite often.
He was not heat to wind, just had his sheets out and sails flogging.
It seems like a poor strategy, I like to hit the line at full speed when I start. But it used to be, a luffing boat had no rights.