I thought of a different kind of embarrassment when I saw this.
Keep in mind that I am one who doesn't believe in 'unconditional positive regard', inside or outside that little room.

How much risk of derailing therapy is there, in talking about the disconnects? the days T was a little 'off', the careless judgmental word, the wrong reading of a comment, the failure to validate, the failure to encourage..... the effects of mixed messages (like someone posted recently, the email me any time and then no answer kind of thing), etc?

wouldn't a T receive mention of say just a few of these, as resentment building up over time in the client? when on the contrary, these things were not talked about at the time out of a feeling of respect and realization that Ts are people too, no one is perfect, etc? still the pile is there, and starts to teeter a little....

Sure it's better to mention something when it happens; but not everyone can do that, and then the opportunity is gone. Unless it's brought up again later with other things and then what is the degree of risk?