I wouldn't say anything, you don't know for sure if he thinks your a shopper. My grocery store (I do often),
everyone knows me, acknowledge's me, and that's a good employee remembering customers, great way to get a nice tip. I'm sure the client will let the MSC know if you've been spotted. Most people go to their favorite restaurant over and over. Sounds like he's a friendly guy, leave it at that.
@Lady Marius wrote:
It is not an official rule for Chipotle to use the third person, it is a suggestion to help keep mystery shopper identification to a minimum. The editors are probably changing your reports to reflect a third person perspective for anything they deem memorable. I save them the trouble and write it that way to begin with. If you are part of their facebook page you would probably already understand this unwritten, unofficial rule. It is unique to that MSC, but I now use it in my other reports for other MSCs as well. That way you can give the associate credit without making yourself memorable.