The only gift I've ever given T is a small rock that I collected while on a trip. I didn't know if he would accept it or not, but he did, and its with the other little decorations in his office still (including some other rocks; he has some little things like that in the office).

I agree with the others that you should talk about it with your T if possible, and that, while maybe understandable that he is wary of accepting gifts (especially working for an organization like that), he should be able to handle it in a kind way, and not make you feel ashamed!

I also think there is some possibility that he was caught off guard, felt a little uncomfortable about the rules, etc., and therefore responded in a less appropriate and caring way than you would have normally expected.