They regularly get free rushers with their disguised blitzes, but they also always have DBs playing deep zones and waiting to jump misguided home run attempts. Their LBs tend to take fairly deep drops, as well.
When the Cardinals got down early, they were forced to throw downfield, which is when you are most vulnerable to Houston’s design. It was the perfect storm, and Bobby Petrino and his star QB were trapped in it all night long.