Unless someone is in a very fragile state, or their condition is such that they would respond badly to such a disclosure, I think it can be a good thing to have occasional moments like this. It's a bit of emotional RL within a relationship that provides a frame for response. It's very honest. Your T sounds like he will take the time he needs, but I would suspect he'll also be sensitive to feelings you might have and encourage you to voice them. And then, move past them.

I think a condolence card is always appropriate.