IMO the plan was to run clock to make sure NE had no time left regardless of what happened on the drive. They still planned to take a shot at the TD. Which they did, but a great play by the DB foiled that. At worst they figured to get 3 points and leave no time for NE. They succeeded at that. (Despite Davis who was the only one who seemed to think a snap was coming). The strategy is sound game management, but IMO it would have been more believable with Tua in. I do get that they may have thought leaving Brissett in would give more time to hard count.