Chronologically:
1) He asked you out.
2) You said yes.
3) You backed out.
4) You stayed friends (i.e. - he didn't hold your backing out against you).
Did you mess up? Maybe a little. He won't ask you out again because he will be afraid of either A. getting rejected again or B. being too pushy.
So now it is up to you. If you like him, ask him out. On a date. Most guys will not mind this. And it will alleviate his worry about being too pushy towards you. Ask him out. Tell him you have thought about it and you do think there is something there that you would like to explore.
Good luck.
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