I know some of you are very knowledgeable about canine behaviour so might be able to proffer an explanation?
He has been toilet trained since a young pup with no previous issues. He was barking to go out but I wasn't letting him since the builders were laying cement outside and moving heavy equipment and diggers - however he hadn't been indoors long; we had returned from a long walk just an hour and a half previously so he couldn't have been bursting for a wee.....
I turned around to see him mid pee - I yelled in surprise and he stopped immediately but didn't look particularly chastened.
Whats going on? Could it be that he had got himself excited by the builders walking backwards and forwards past the French window, had been keen to get out there to bark manically at them, and the frustration and pent up excitement at not being allowed out to go and see them off caused the peeing?