In the 1 minute post-race interview on American TV the interviewer asked Gay “you pounded your fist on your thigh after the race, were you disappointed?” Gay responded “I can run that fast, it just didn’t happen”. He also said he was happy with his time and thought Bolt was phenomenal.
It sounds like he believes he has more in him. With the injuries the past two years and the still great times he’s posted I can very well see why he believes he hasn’t maxed out.