Ask HN: Spookiest Recommended Connection

About a year ago, I had the unfortunate experience of an ambulance ride. As per protocol, an attendant rode in the back of the ambulance with my wife and I. The attendant talked to me most of the way, making small talk for about 20 minutes, I believed to make sure I stayed alert and lucid. I don't remember his name. But I remember his face pretty vividly. A few weeks later, I was connecting with some new business acquaintances on LinkedIn. After each connection, LinkedIn served up a set of recommended connections. In one palette of faces, I saw one I recognized but couldn't name. His company was 'American Ambulance'. It was the attendant. After I got past the shock of realizing this, I spent a fair amount of time trying to figure out how LinkedIn made that association. I had no contact with him before or after the ride. I made no social network contacts with any other person involved in that ride or the subsequent emergency room visit. I still can't sort it out, except to conjecture that he and I traveled the same route at the same time in close proximity and LinkedIn somehow obtained that information. Did we both have the LinkedIn app active during that ride? Do people riding in the same bus at the same time get suggested as connections? What is your 'spookiest' recommended connection? Or, in other words, how else have we tendered our privacy?