Welcome to forum.
He might be telling truth about you being friends. But that might be not all the truth hes saying. If a guy messages girl late at night them shes not just a friend to him. I think theres more to it. You should instead ask him does he likes you or finds you attractive.
Sometimes I been messaging girls I liked more than friends in a friendly way because I had no experience in being romantic or I was holding myself back because girl was too young or too far away from me.
Often I would give up and kept it friendly just to find out that girl is not given up yet. So I continued and beautiful things happened.
Bottom line is guy could have been afraid to admit that he sees you more tgan a friend in case you dont see him more than a friend too. Besides you kept it friendly so he answered correctly that you are friends. Would be weird and very brave if he would say something more than that.
Doubt kills more dreams than failure ever will