It's not so much a case of ruining a round Robin.
As I said in the OP, I can usually switch off from his antics, but when it affects the group as a whole that's not good.
He has a reputation at work as regards to his attitude so, as you can, imagine people don't want to play with him.
I don't normally have an issue, I hit my shot and switch off until I have to hit another. I just found it strange how I couldn't Saturday.
I think its affecting you more than you realise, especially if you are concious its affecting others in the group, your then thinking about the affect its having on them and subconsciously all that's running around in your head! I think its time to have the wounded animal put down