The Bears' pass defense came into the game ranked 12th overall (203.8 yards per game), but cornerback Jerry Azumah got beat by wide receiver Corey Bradford for a 37-yard touchdown in the second quarter.
Azumah dressed in a hurry after the game and did not talk with reporters. He didn't have the safety help deep that should be there in a cover-2 zone.
"Only one guy was out in the route and he shouldn't have been able to make that catch," Smith said.
The other pass was a 69-yard completion to Jabar Gaffney that set up a field goal for a 10-5 Texans fourth-quarter lead.
"I think they were just mental mistakes," Bears cornerback Charles Tillman said. "I don't ever think you can play too physical. Let it be known that this is a barbaric sport that we play. So there is physical-ness in this game and I think the more successful you are, the more physical you are.
"I just think you've got to cut out the mental mistakes. We made too many mental errors."
Smith wasn't about to second-guess himself after declining a penalty on fourth down that proved decisive in the game.
The Texans took a delay-of-game penalty on fourth-and-seven at the Bears' 31 to give themselves more room to punt. The cold and wind prevented them from thinking about a field goal at that point. However, Smith declined the penalty and the Texans sent their offense back out on the field. Carr then threw 8 yards for a completion to Corey Bradford right in front of Tillman for a first down. The Texans then drove to a touchdown and a 17-5 lead.
If Smith had taken the penalty, they likely would have punted on fourth-and-12.
"I thought what they were trying to do was move it back so they could pin us down (on the punt),'' Smith said. ""I declined it to offset what they were trying to do. They got the chance to go for it on a fourth-down situation.
"We should still be able to convert (defensively) in that situation.''
The Texans were patting themselves on the back after deciding to go for the first down instead of punting.
"It was a great call by Dom (Capers) to decide to go for it,'' Carr said. ""That was probably the biggest play of the game because we were able to take over, go down and score.
"I'm just glad he gave us the opportunity and wanted to go for it.''