Having been in a career for over a decade with such discretionary power from the get-go, I can tell you that unless you were dealing with an executive, the agent had to account for those tickets to his boss. Not in a bad way, mind you, probably. Many workers at amusement parks, stadiums, and the like have considerable discretion when it comes to doling out freebies. It’s just that no matter what, there will always be an accounting in any such organization.
You could do worse than to send the company an email with what you posted here. On the very small chance that this person did you an ENORMOUS solid by doing something for you which he was not authorized to do, don’t send the image of the tickets or even mention how much they cost.