I wouldn't necessarily bring up OC'ing immediately if meeting such a person again. If through the course of normal conversation OC'ing was mentioned, fine. But seeking out someone primarily to lecture or informthem on firearms legalities won't make them any more open to or agreeable about OC, CC, or firearms ownership in general.... especially if he's European or whatever. Many Europeans have quite a different view on the fact that American citizens are allowed to generally own whatever firearm they want, and many see us as gun-toting, trigger-happyhicks or thugs.
Also, you should check out Liberty's campus regulations on firearms. Even if you weren't directly on school grounds, being very close to it while OC'ing may attract the attention of someone who is fearful that youeither were previously, or are heading ontocampus, and they'll call the authorities. A MWAG call at a college will be taken very seriously, even if you're not actually on school grounds. LEOs & campus security will act as if you're an immediate threat, so don't be very surprised if upon arrival, they use very stern commands and tactics.
I myself try to stay well away from all schools while OC'ing, as people who see someone OC'ing nearby will immediately assume the worst and relay much to the dispatchers.
And make sure you get a quality holster before OC'ing again, if at all possible. Having one that's defective/shoddywill likely only endanger you more than if you were unarmed. Not being able to execute aquick & efficient draw when fractions of a second count, or having a sidearm that's easily accessible to the wrong hands.... well, that's really bad.
But anyways, welcome to OC'ing. You'll get used to ignorant ijits trying to dictate law & opinion about OC, and when someone makes a positive comment it's a pretty good feeling.