Do you think I was mean to him at all?

His response was unnecessary, you shouldn't feel too upset. You were trying to let him down easy correct? You didn't want to blatantly shoot him down? You should have been upfront with him though. Even though you weren't trying to be cruel, you certaintly weren't encouraging further pursuit. Meeting in front of him was a mistake. In all it doesn't sound like you are a bad person to me, or that you had bad intentions. I DO HOWEVER believe you should in the future be more direct and say that you are not interested. Remember it's more of what is meant than what is done, you sound like you were trying to prevent hurting him by rejection or you were too shy to reject him straight up. Don't be hard on yourself, you had no malicious intent.