Hang on, when you say "reputable shop in Portland" - was this one of those places that sells a lot of handmade, artisanal stuff where the owner talks about "rockwell hardness" and "cryogenic tempering" for like 20 minutes? I only ask because I've run into a couple shops there that push these super-hard, thin-bladed knives (like 62-64 HRC) that are basically meant for slicing raw fish and fileting, not smashing through squash. The chip sounds like it came from twisting or torquing the blade while cutting through something dense, which yeah, a lot of those high-end gyutos just can't handle. Did the shop tell you anything specific about the steel type or the heat treat, or did they just go "oops, that's on you"?

Man, that's brutal. I feel your pain. Same thing happened to me on a boiler tube pull a few years back, I was cussing up a storm. I tried everything, wedges, heat, but that tube just rolled into a pretzel. Ended up like you, grinding it out in chunks. @the_brooke is right about the penetrating oil and the slow pull, but I also swear by using a tube expander to loosen it up a bit before I even try to yank it. That one trick has saved me from a few 6 hour nightmares since. You just gotta respect that metal sometimes.