"They have scored from set plays and things we have talked about so it is two mistakes really," he told the club's official website.
"When you are a coach and you walk through things on the training pitch including the long throw from Gunnarsson you want everyone to mark properly.
"But the flick on comes and Fraizer Campbell runs in and scores and that drives you mad as a coach and makes matters worse. We'd showed it on the DVD and it's one of those goals that keeps you awake as a manager."
The loss means that Wolves remain 22nd in the Championship standings and are two points from safety.