I am going thru a similar situation and T's openness has been really helpful for our work. I get to see him model vulnerability and taking appropriate emotional risks and in response I have been more vulnerable in therapy and with my relationships in my life. there has been a profound shift in how I see myself and observe the ways in which I relate to others that aren't healthy for me. our therapeutic relationship is close but at times incredibly difficult. because he has been vulnerable (admits mistakes, willing to talk about our ruptures etc) I feel like we repair easily and each time the bond strengthens. it might not be ideal for some clients but I think your T was awesome for allowing you to experience him that way. a card is a lovely gesture and also bookends the aspects of his disclosure that aren't focused solely on you.