You had a few rides in the car, did he even go into boost for more them a few seconds? A friends intercooler pump went out and it would boost for a few seconds and then go into limp mode because the heat exchanger temps were to high. It might be that the heat exchanger could've cracked due to freezing, leaked into the cylinder and went past the rings into the crankcase. The car probably wouldn't turn over on the first try because it might have been on the verge of hydro-lock.