A little deflated ??????

Had to rescue the sister in law to be this morning, a flat tyre on her way to college ??? She'd run it flat and destroyed the tyre but on closer inspection it seems to be the valve that's caused the flat in the first place ??? Although I've never seen this kind of valve malfunction before ? She did say she scraped the wheel on their driveway gate post on the way out this morning but there's no damage to the wheel trim at all, just this valve sliced perfectly open ???
She's sorted now with a replaced tyre, valve and balanced wheel :)