I tried to promote a mason right before a goblin raid. He’d gotten to the mallet and chisel right when the goblins reached my stockpile. I pressed the button for Town Defense mode. Unfortunately, he didn’t listen. He tried to pick up his new tools, but two to three goblins surrounded him.
They hit him. He dropped his tools. He started picking the tools back up.
That process repeated (and his health depleted) until I called off the town defense long enough for some other Hearthlings to run away from the goblins - towards him (and the goblins around him.) [AI is weird.] I called town defense back on and they were able to distract the goblins, and he was finally able to pick up his tools all the way, and finally be promoted.
Then a stray blow hit him and he instantly died.
How could this have been averted? I see two ways. If he had only picked up his new tools without responding to the hits, he could have been promoted, and then gone back to fighting without losing as much health as he had. Or combat directly around a Hearthling could have a higher priority than promotion.