Sounds a lot like the way people extract THC for oils like RSO. They soak buds in everclear (or the most potent alcohol available) which pulls the the THC off the buds (if you're going to try this at home make sure you decarb first). They use a warmer to evaporate the alcohol off it & leave pure THC. Sounds like he was skipping the last step of burning off the alcohol leaving a potent mixture of alcohol & THC.
That's called a FECO, Full Spectrum Cannabis Oil. It's kind of a hassle to evaporate, so I just use the tincture in a mixed drink. If you do a Golden Dragon, taste isn't that heavy. Green Dragon, that's another story.
Here's my go to site for recipes:
https://emilykylenutrition.com/recipes/
Lots of good info and haven't had a bad recipe yet.