Have you ever heard of the phrase "Actions speak a thousand words?" You initiated the hostilities with your action. Even if she was the worst CSR in the world and you only had a 5% chance of getting help, you might have blown that small chance right outta the ballpark. It really is pointless showing anger towards someone who had nothing to do with the damage to your bag. I'm not excusing her actions and response, but maybe if you had approached her without the chip on your shoulder, maybe things might have been different. I'm not trying to insult you - just saying displaying hostility to someone who did not deserve it to begin with doesn't normally elicit a pleasant response. People are going to respond differently to hostile words or actions. As for Elite tags on your luggage - that doesn't mean they're going to put their white gloves on and treat it any differently than any other passenger's luggage they handle with one exception - a chance that it may show up at the carousel a little earlier than the others. No more, no less. That is the sole meaning of that tag. Any other expectation in that regard is misguided.
Good luck w/ the bag. If the release button was on the handle, that might be an argument - that the only way the handle could be extended was if the button was accidently pushed and the handle extended by an UA employee. If I was a handler, I wouldn't take the time to go out of my way to find a handle release.