This guy had a crush on you - big time!

You seem like such a genuine, caring person from what I can make out in your post.

My opinion is, you've done nothing to warrant this. At each step of the way, you were upfront and honest with him about where you stand in terms of commitment and relationships.

Whilst he may have "heard" the words, he may not have internalised them because he was so smitten with you.

Some people may have questions (your mutual friends) but common sense would tell any level headed person that you're in the middle of studying, you're on committees, you're 19 and he's much older etc etc. So let them wonder, or you could just explain yourself if they ever ask.

He's probably a little heartbroken but don't let that manipulate your into seeing him any more than you have to. You were right in not leading him on and being blatantly upfront all the time. Guess he just couldn't take no to no relationship seriously.