German Week - S3-E6
Revealing mistake: When Mr. Humphries and Mr. Lucas make their toast with the German mugs, Mr. Lucas' mug breaks but Mr. Humphries' does not. A moment later, when Mr. Humphries notices the mug has not broken, you can see that he crushes the mug with his hand.
Answer: That wasn't possible in 1972. Until recently squatting was a civil offence in the UK, not a criminal one, and removing squatters was a complex and time consuming business.