Sam Hutchinson saw red on his return to Sheffield Wednesday duty as the Owls crashed to another Hillsborough defeat.
The midfielder was twice booked after coming on in the second half as the Owls chased the game, trailing to two first-half goals from Liam Feeney and Darren Pratley.
Chris Maguire handed Wednesday - who hasd started very poorly - a lifeline with a first-half penalty after Atdhe Nuhiu was fouled in the box.
Wednesday played much better in the second half and deserved a point, but Nuhiu and Claude Dielna saw their shots crash back off the woodwork.
And when Stevie May netted from the rebound, after Nuhiu’s effort, he was given offside by the officials.
Wednesday head coach Stuart Gray said: “We started so poorly and then we gifted them a second goal so we gave ourselves a bit of a mountain to climb.
“We got back in the game with the penalty and it was hard enough playing Bolton with 11 men, but then with Sam (Hutchinson) getting sent off it was very, very difficult .
“Credit to the boys because they stuck at it. We’ve looked at Stevie May’s goal and he was onside. We’ve been punished by a poor decision.
“We had a go in the second half and we had to push for the equaliser. Credit to the players for having a right good go.
“They’re a big, physical side and they bypassed the midfield. They know how to kill the game off, which was frustrating.”