Does "I love you" count over the phone?

I was speaking with my guy friend over the phone and I told him I loved him, and i meant it. It just sort of flew out of my mouth, I was having an emotional conversation with him and I wasn't thinking. He said he loved me back, but i couldn't tell if he just meant it in a platonic way or because he knew I needed him. I could tell there was a smile in his voice and he seemed surprised when I had said it. We then started telling each other we loved one another every time we talked. He'd say it first sometimes. Now we've lost contact (it's been years), and I'm still wondering what the hell happened. I fell for him hard, and I could never tell if he loved me back (although I thought he really did when he looked me in the eye, but we never truly discussed it so I was never sure). I still love him to this day, it's been four years. How do I know?