Interesting. I got the golem out again and can't attack it. It turns green when the mouse is on it but no other reaction. The first time it could be attacked and then eventually started beating his owner to death, like the hirelings at the Jhelom Pits will eventually do after being passive targets for a while.
The first time the dagger did a couple points of damage per hit but the golem's healthbar stayed blue other than the last couple of pixels. Weapon was a 100% poison damage mage-weapon dagger.
I take it this is why there has been no one golem-whacking at Luna hour after hour after hour at Luna anymore?