Last downwind ADS-B report had him S&L at 80Kts, with almost direct crosswind (NW at 9G13 - so GS would be virtually identical to IAS). I'm not seeing anything close to a stall from the ADS-B data. It's almost like the beginnings of a spiral dive - but WTF would trigger that at the base turnpoint?!?
Here's the replay from ADS-B Exchange