WJQ McGrath
Training officer at Aldergrove in my time ( 1964/5 ) I understood that he was William James Querke McGrath, that he was indeed the aircrew member who walked over the mountains to freedom on a broken leg (the version I was given was that he walked over the Alps as an escaped prisoner into Switzerland, rather than as an evader into Spain, but heroic either way!)
He was known simply as "Q" or "the wee man"