Watch and learn, it happens on 1:22 https://www.youtube.com/watch?v=jUuh80uqCnA
It might be possible to spam kegs and trooptraps. Because of this bug you can use abilities twice in a row. It happens just before you're about to fall.
If you let BFH think you're falling and landing the whole time on command, you can spam Keg TT BS GS!