"Dr. John Watson. Former RAMC." John brushed a hand against his thigh, more to shake off the constant unsettled feeling that plagued him than any germs. He frowned; the woman's accent was American. Perhaps he'd best explain the acronym. "Royal Army Medical Corps. I'm, ah. Retired."
It was simpler than explaining that he'd been hurt, and John didn't feel particularly inclined to give out that information, anyway.
After a moment's thought, John turned and headed back for the bench. He wasn't ready to go in, and if the strange woman were mad, she was the sort he felt he could understand.