And Wales made the extra man pay, ruthlessly running in six further tries to hand Scotland a record defeat in the Championship.
It left Scotland finishing fifth in the table with just one win, coming courtesy of Duncan Weir's last-gasp drop goal against winless Italy.
Hogg himself apologised for his actions following the Wales clash, but Gray, while acknowledging his side's effort, believes the rest of the players should have restricted any further damage done on the pitch.
"We are all embarrassed by that result," Gray said. "At this level, to get 50 put against you just should not happen.
"After the game, the heads were all down in the changing room. We wanted to put in a better performance than we did but we feel like we have let everyone down.
"It was very tough to take. We went down to 14 men but even then we should not have conceded as much as we did.
"I can't fault the boys for effort and heart but we should have played a little smarter. We need to get the details right when situations like that do arise. It's a very sour note to finish the championship on."