this elder suddenly realized that he had NO control over me.
I doubt you were reading anything into it. It is a very real look. It sends them into confusion, and they don't know what to say to regain "control".
I've seen this look twice... in the last year before I was df'd. By this time I was mentally "out", but in for family. One time, after a long stretch of missing meetings, I was at home, doing spring cleaning. I had missed the Sunday meeting, and the CO came by to "encourage me". I came to the door, jeans & t-shirt, hair in a pony... my hallway messy with boxes and bucket & mop. He said he missed me at today's meeting, and wanted to know why I wasn't there (I didn't look sick or depressed ), so I said I was Spring Cleaning. He got the "elder look" and sternly asked me if I thought that was more important than the meeting (trying to make me feel bad or guilty - hey, isn't meeting attendance voluntary???)... anyhoo, I looked him straight in the eye, with a big smile and said "Yes. I needed to get my house cleaned".
He got that look... that "I don't have control" look. He didn't say anything... he just stood there. I asked if there was anything else, and he said "no, just wanted to make sure I was OK". I said I was fine, thanks for popping by, and closed the door. It felt great.
The other time was even more funny... happened at the Kingdom Hall infront of everyone.... but I'll save it for another time.
Awesome the way you handled this though! Feels great to be "there" - to be free in every sense of the word from that cult.