The insider scoop, direct from Cardiff:

Today, the truth has been revealed: The actual reason actor David Tennant had a reduced role in episode 12 of Doctor Who, wasn't due to story considerations, but because of the fact that just before filming began, Tennant challenged his co-star Catherine Tate, to a drinking contest, as pictured in the above photograph, obtained exclusively by this blog.

Tate won the contest, hands-down. Crediting the fact that ginger-haired English women hold their liquor better than skinny Scottish men, Tate said, "I am woman,(hic) hear me roar!" Tennant responded by throwing up on producer Russell T. Davies designer shoes. While Tate recovered from the drinking bout fairly quickly, Tennant spent the rest of filming with his head coming in close contact with a loo bowl.