Boro failed to find the net for a fourth time in five games and have now won just twice since the turn of the year in the Championship.
"I don't think there was much in the game," said Mowbray.
"From my eyes I thought we were probably the better team on the day, probably created more chances. I thought it was a tight game, not much in it."
Robbie Brady extended Boro's winless away run to 10 matches when he curled a free-kick low around the wall to catch out goalkeeper Jason Steele, who could only push it into the roof of the net in the 62nd minute.
Mowbray added: "It's straight at him, whether it's took a bobble off the pitch or bounced high, I think it's straight at him and ended up in the roof of the net.
"That's football, that's the way it's going for us at the moment.
"The statistics are quite damming of how many games we've won in the last 14, 15 and yet we can look back at a lot of those games, like today, and think we didn't get what we deserved.
"But you've got to put the ball in the net when you have opportunities and we haven't done that consistently enough."