I am not sure that it is based on a specific event but 1972 was a very tense year in the British government:
- 2 separate states of emergency were declared due to striking
- Bloody Sunday
- The British Embassy in Ireland was burned down
- There was a very violent protest in Derry
- Aldershot was bombed with several people killed
- 2 British ships were sunk by Icelandic battleship
- The Government introduced pay freezes
All of the people in the club would have had strong opinions on all of these subjects (and more). I would have been amazed if they did not discuss it there and discussions on emotive subjects can easily become shouting matches!
The only real way to stop it would be to stop anyone talking about anything so people know that they can come somewhere just to relax.
Incidentally (slightly OT), when the politics in my re-enactment group became very bitter and nasty (yes, really!) my wife and I banned anyone from discussing it in our house. Our house became a popular hang out for many of the people involved because they knew they could relax. No one had been allowed to blacken their name so they did not need to worry about explaining their side of things.