"The first goal has taken a deflection off Emmerson Boyce, and it should have been dealt with in the wide area before it came in," he told Sky Sports News.
"The second goal was just a hopeful punt up the field, which we've allowed to bounce, and we had two opportunities to clear but failed to.
"We're not shutting the door at the back, and ultimately you're paying a heavy price for that. Having said that the character was there in abundance and we could easily have won the game."
The result leaves both Wigan and Boro with five points from their four games so far.