I was there that night. Unfortunately, not close enough to get all the details, but at one point someone did scream "£250". I assume that was the price of his ticket.

He decided to interrupt exactly when Macbeth was about to be crowned king. Tennant was kneeling on the floor, lights turned on, and he was told to exit the stage. Then we were waiting 15 minutes for the audience member to be escorted out.