He had two good chances early in the second half and messed both up, probably lingered in his mind for a while and the booking didn't help.
It's one thing Gabriel deserves praise for, whenever he's messed up this season he's redeemed himself in the same game. Lost the ball vs Mitrovic and scored the winner later vs Fulham, today's first goal was mostly his fault and without sprint deep in injury time of the first half we most likely don't score our second.