Starting to realize Uncle isn't totally on the wrong here.
His social (and romantic) incapability aside, he was slugged so hard he was knocked out for heavens knows how long (and a hit like that had to break or fracture something that hopefully a doctor or magic could fix). Over some tsundere being possessive about his clothing (which was probably an important personal memento of the world he was summoned from). Apparently anime harmless slapstick rules stop applying when you're older than 30.
That cannot be a good memory to link to the poor elf girl.