Coventry, without a win since September, went ahead through Leon Best before QPR looked to be heading for victory after goals from Jay Simpson and Akos Buzsaky.
Magilton said: "I'm extremely disappointed. We didn't defend at set-pieces and I'm angry about that.
"Matt Connolly has to take his share of the blame for the first goal. If you're marking someone then you need to take responsibility.
"For the second goal the keeper (Radek Cerny) should have done better.
"I'm angry because we were very good with the ball. We were confident, extremely bright and passed it well.
"But you also have to take responsibility and defend for your lives. That didn't happen. We fell asleep at set-pieces."
Best opened the scoring when he beat Connolly to Patrick van Aanholt's free-kick and sent a looping header beyond Cerny.
Simpson levelled 10 minutes before half-time, latching onto Alejandro Faurlin's chipped pass to nudge the ball past goalkeeper Kieren Westwood.
Adel Taarabt hit the Coventry bar with a delightful chip from just outside the penalty area before Rangers went in front in the 70th minute.
City struggled to clear Faurlin's corner and the ball eventually dropped to Buzsaky, whose left-footed drive went in via a deflection off Wood.
But Wood, recently signed from Sheffield Wednesday, had the last laugh by heading home Michael McIndoe's right-wing free-kick.
A delighted Coleman said: "Teams are going to come here and struggle, so this is a big point for us. Hopefully this will give us a platform to get that next win.
"Collectively, we were better. We were a bit too route one at times, but that's because we're lacking confidence at the moment.
"In the first half we did well and could have been 2-0 up. In the first 20 minutes of the second half we couldn't get near QPR but, having said that, their second goal was a deflection.
"Then we came back. We were forceful, which we needed to be. Credit to the players for getting something out of a difficult game."
Wright was dismissed for a second bookable offence following a foul on Buzsaky with four minutes remaining.
The defender angrily threw his captain's armband in the direction of referee Mike Jones after being given his marching orders.
"It wouldn't be like him to do something like that," Coleman insisted.
"I've not talked to Wrighty about it and I didn't see it, because I was organising the team's formation after the sending off.
"It was a foul, but I don't think it should have been a booking. Buzsaky went down a bit too easily for my liking."