Preceded by a tight base to final turn.
Likely cause: accelerated stall due to low speed with high angle turn and inadequate altitude to recover (he probably pitched up as well in fear instead of attempting a recovery).
310's are especially unforgiving on that. Highly loaded wing and he probably didn't have full flaps.
You DON'T get low and slow in a 310 and start doing wild maneuvers.
...if so, guess he's lucky he didn't lawn-dart.