when someone uses a personal experience to bolster an argument, it is appropriate for someone to question the validity of how likely it is. It's not an ad hominem or a personal attack.
Next time, perhaps phrase your argument around your experience. "While I don't know where you're from, I never experienced this. Where I grew up in XYZ, people were quickly corrected regarding their misconceptions."
Best not to be 'pretty sure' with accusations, even mild ones, especially when you're apparently wrong. And why are you pretty sure? Seems like you have some reasoning, mention why with your accusation or your viewpoint will be 0 on the contribution scale. It comes across like a child discussing whether or not he thinks Santa is real "Yea I'm pretty sure he exists and you're making it up"