Do I know you?

It's the question every deputy/CO hates while they are out in public off duty. Yeah, you know me. I arrested/processed/restrained/transported you. Do I really want to tell you that in front of my family and yours? Probably not. I usually just smile and then they suddenly realize the connection and quietly move on.
This morning I had a very disturbing encounter while paying for my breakfast. I hand my bill and my cash to the lady behind the counter. I'm not really looking at her because I'm with two dispatchers, all of us in civilian clothes. Halfway through making my change the cashier bursts into tears, and sobbing, tells the other clerk to give me my change as she bolts for the door.
Awkward.
The new cashier looks at me and goes "I guess she knows you." "Uh, not that I'm aware of." I have a fairly good record with faces, and I swear I didn't know the first cashier from Adam. I feel pretty weird about this. Obviously this lady recognizes me and it is not a pleasant reminder of something. I try to be a decent officer and treat people with respect. However when I was a new officer I was a little badge-heavy and that's not something I am proud of. I know that I am a better deputy now than I was for the first two years, and I also know that I could use some improving. I have no idea what I could have possibly done to this woman.
Again, disturbing.