What team and when was the last penalty awarded to the away side at Old Trafford?

It was on the 17th of March 2007, against Bolton, when Nemanja Vidic was harshly adjudged to have pushed Faye. In that season, United conceded three penalties at Old Trafford - against Arsenal, Wigan and Bolton. Many people argue that referees are biased towards the big four when it comes to decisions like penalties, and point to the fact that these teams concede fewer penalties than others, and gain more penalties than others. While the fact that big teams tend to concede less and gain more penalties than others is undeniable, you have to look at other considerations. The bigger teams generally have more possession than their opponents, and spend more time in their opponents penalty boxes. So obviously, they are going to get more penalties. if you spend 10 minutes of time in your opponents penalty box, you are twice as likely to get a penalty than your opponent if they only spend 5 minutes in your penalty box, right?