This triggered a memory from my second "real" job.
We had a secure building with glass entry turnstyles. In my second week, a suited important-looking person was standing behind the gates at 8:20AM (we started at 8:30AM). It was busy and everyone was ignoring him (that seemed odd).
The suited guy picked me from the line of drones going through the turnstyles and asked if he could jump in behind me (he didn't even mention if he worked for the company).
I was still doing the HR training program stuff (the general wear deodorant, don't plug in flash drives from outside, don't ask for teamviewer, etc stuff) and the last thing we did the day before was end on the tailgating policy.
I told the suited guy that I couldn't let him in due to company policy. He smiled and said "all good" and went back to the corner.
He ended up being the head of logistics. Apparently, he liked to scope out the new hires and "test" their compliance. He tried this with 5 or 6 of the new hires and only managed to get let in once. The lady that let him in wasn't fired, but she did get a warning.