Wasn't Wyn Evans was it ? - seem to recall that's what I got told too
Top chap - Wyn was on my Gnat course. He once went into a shop in Llangefni and the locals did their usual trick of switching into Welsh and make disparaging remarks about the English.
Little did they know that Wyn was not only Welsh, but spoke the language fluently. So he listened to this for a while, but when he paid for whatever it was he was buying he conversed with the shopkeeper in Welsh before 'rebriefing' the ignorant local yokels who'd been insulting the English!