AITA for refusing my uncle's hug in front of the family?

I stepped back and held out my hand. My uncle opened his arms wider and said, "Come on, don't be so formal."

I said, "No hug, thanks." When he reached toward my shoulder anyway, I said more loudly, "I already said no."

We were arriving at a family lunch. I hadn't seen him for months, and he normally hugs everyone. Nothing bad had happened between us. I simply didn't feel like being hugged that day and thought a handshake was a friendly alternative.

The entrance went quiet. He dropped his arms and walked into the dining room. My mother said I could have tolerated a brief hug instead of making him look unwelcome. I told her the handshake had been meant to welcome him.

Later my uncle said he'd thought I was joking at first, because I usually hug him. He apologized for reaching again, but said the louder response embarrassed him. I said I didn't know how else to make the answer clear in that moment.

I sat beside him during lunch and talked normally. Mum still thinks I used a small preference to make a point about the whole family. I wanted one interaction to go differently, not to stage a demonstration. AITA for saying it loudly?