Interairline baggage checkin with two tickets
Let me add a twist. Were you polite? Flashing status on face doesn't really board well with most airline employees. I ask this as you mention that he 'sarcastically mentioned that he could cancel your tickets'.
I have been in similar situations numerous times and never had an issue. Just be ultra polite as you are on the receiving end. I doubt you will get any positive resolution in your favor.