ARLINGTON — Detroit rallied from a 27-3 deficit to shock the Dallas Cowboys 34-30 Sunday at Cowboys Stadium.It was the biggest collapse in Cowboys history, according Elias Sports Bureau. The largest was 21 points against Washington on November 28, 1965 at Washington. The Redskins won the game 34-31."I don't think anybody relaxed," Jason Garrett said. "We didn't do enough to win the game. Hopefully we can step back from this disappointment and learn from it."Dallas led 27-3 with 12 minutes, 23 seconds left in the third quarter.Detroit's defense led the comeback with back-to-back interception returns for touchdowns off Tony Romo.Former Cowboy Bobby Carpenter returned the first interception 34 yards for a touchdown. On Dallas' next possession, Chris Houston returned an interception 56 yards for another Detroit to make it 27-17.A Dan Bailey 23-yard field goal pushed the Cowboys' lead back to 30-17.However, Detroit's offense finally began to click.Matthew Stafford threw a 23-yard touchdown to Calvin Johnson, who was tripled covered, to make it 30-24.After an exchange of possessions, Jason Hanson added a 51-yard field goal to pull the Lions within 30-27.A third interception off Romo, this time by Stephen Tulloch, opened the door for the Lions to complete the miracle comeback.Eight plays later, Stafford hit Johnson from 2 yards out for the game winner and a 34-30 lead.Dallas reached the Lions' 45, but two incompletions, a sack and a short completion to Felix Jones ended the game."The game turns on turnovers. I should not have allowed them to have that chance," Romo said. "I was disappointed on the decision-making on a couple of those throws."