I have had that style of torch for more than 30 years and have never had
it more than "poof" when triggered off the "tank".

I just did the following: let it burn upside down for a minute, then let
it sit upside down for 20 minutes. I took it off the tank and triggered
it - it only poofed.

The guy is not a troll - he has hundreds of videos on YouTube. Mostly
about artificial reefs and his farm. BTW - he is not a farmer - he is a
vet with an 80 acre hobby farm. Very sincere.

I don't think that his video is faked. The only explanation I can
advance is that his torch is defective. I had another brand of
all-position torch once that was not working right & I tried to fix. In
taking it apart, I found that it had a separate chamber that I assumed
was for vaporizing liquid propane that was delivered in the upside down
condition. Perhaps his torch is defective in letting liquid into this
chamber (which, IIRC, could hold 5-10cc). Wait ... I just re-watched
and he said that he had it happen on "several" different torches. So, I
dunno.

However, it's not the brand of propane. He says that some brands let
propane "leak into the torch" when they're off. That is just plain
ignorant! Anytime a torch is attached to any tank, the tank's integral
valve is opened and gas enters the torch.

Another thought: he is in winter clothes in the video & maybe the
(Minnesota) winter temperature has something to do with it. Let's see:
if you put the torch on a _warm_ tank and let it sit in the cold, the
gas in the tank would have a higher vapor pressure than gas in the torch
chamber and you would get transfer. Vaporization in the tank and
condensation in the torch. It's possible.

Bob