If the watch was seriously overheating constantly, I wouldn’t try to take the bands of.
If it wasn’t, there certainly is info missing from this story.
I think there’s info missing anyways. For example, the Apple Watch Series 7 has a battery life of less than a day. I can’t see that getting longer when it’s overheating. Even if this occurred overnight (“over 2 days (at least)”, IMO, is not what the article says. It could have started overheating at night, and ‘exploded’ early next morning), did he try to recharge the watch after Apple told him not to touch it?