Houston had four scoring drives.
The first one featured a silly 15 yard penalty against Eric Rowe after the Patriots had gotten a stop on 3rd down. That opened the door for them to get down the field for a FG.
The second one came after a tipped pass INT of Brady, giving Houston the ball on the Patriots' 27 yard line. They gained 6 yards and then kicked a FG.
The third one came on the fumbled kickoff, giving the Texans the ball at the Patriot 12. That led to a TD.
The fourth one came off another tipped pass INT of Brady, giving the Texans the ball at the NE 34. They gained 6 yards and then kicked a FG.
So that's 16 points. 13 of them were due to being given a short field by bad, uncharacteristic turnovers. And the other 3 came thanks to a stupid penalty which kept the drive alive.
In other words, the Pats' defense played really well.