It's a minimum of 4 minutes. If I recall correctly, the ball went out for a corner at least once, it also went out for numerous throw ins and there were 1 or 2 free-kicks during the time as well. So, surely that adds up to 15 seconds?
Hence where the 15 seconds of play came from for Darren Bent to get his goal. Simples.
sure you'd have a different opion if it was Man utd.