Totally depends on the gent.
The first time I unexpectedly (in an airport) crossed paths with someone I had hired, the gent didn't seem to notice let alone recognize me.
The next time, it was in a busy casual restaurant with nearly all the tables occupied but open seats available at the table where I was sitting. I noticed that a duo I had met with had their food and were looking for a place to sit. As I shifted my things to indicate that the seats at my table were open, one of the pair seemed to recognize me. He whispered something to his partner, who glanced quickly at me. They stopped looking for a place to sit and took their food to go. It made me a bit sad as it happened but I totally understood.
Another time it wasn't unexpected but was a situation where I had arranged for the gent I had seen the previous night to also see the show I was seeing. When I arrived to the theatre, I unexpectedly bumped into a group of friends. As the gent approached, I stepped away from my friends to greet him as I would any friend and I gave him his ticket and then returned to chatting with my non-pro friends. I don't know that I even offered an explanation about the gent.
But, yeah, always follow the gent's lead...