Yep, that's pretty much I was basing everything off of... I aspire to be more Fe, but because it's still developing, it comes off as awkward, forced, or out-of-no-where sometimes. I'd feel pretty comfortable telling a friend of 2+ years I was very close to that I loved them. I may even use a situation where they're feeling vulnerable or down about something to first say I love them and be affectionate (like how you lost your friend) because... well... I'm an opportunist, and I'd feel like I finally needed to let them know I care (because I know my indifferent persona may come off as uncaring to some). After that, I'd probably be more frequent with my affection. However, if I was -in- love with someone, I'd need a HUGE amount of reassurance from that person and their feelings for me before I felt comfortable telling them I loved them. That's probably one of the more vulnerable and exposed positions I can be put in, and I would not act as casual as you described your friend to be.As I'm maturing, I'm becoming more open to my friends and family, not necessarily saying since it's difficult to find the words, but doing things to let them know I care and value them. They know I'm very reserved and private, but I don't want them to perceive me as cold and disconnected because that's not me at all, so I'm slowly finding my ways to give love.
Your friend told you he loved you, and expressed how special and rare that was for him to say it. I would completely agree this is the same for me, especially with close platonic friendships. It would be much easier for me to tell a close friend I loved them, than it would be to tell a woman, whom I was in love with , that I loved her because I feel much more vulnerable in that situation.