SawTroll
Information Collector
Hello Madhatte, I think it's a species specific thing, like spruce or other swelled butt wood. If the butt is swelled all around, it might be a good call to flare it before felling. The only positive result seems to be that the butt log looks clean and we're only gonna get paid for the tip dia. So I think the mill or the log buyer digs the funky cuts more than the faller does. Lol Plus, those cut off flared butts ocupy alot less room on the loggin' truck.
Gypo
I think you are on the right track!
Also, his bar looked like it was a bit short, so he had to cut from both sides.