In the version I saw & read the pilot said that he was in weak lift at the time, 1 or 2 knots, so no danger of being sucked into cloud. Judging from the cloud shadow the cloud doesn't look to be that big either, so not hard to fly away.
It's not a full on funnel cloud all the way to the ground though, is it? It looks like it ends barely 100' below him. Given that he's almost at the base of convective cloud the ambient air temperature and dew point must be almost identical. It wouldn't take a lot of rotation to drop the pressure enough to increase the dew point that extra fraction of a degree at the centre of the rotation to create that small funnel.
Nonetheless, very very cool to see in flight.