Re: Hmmm
"He came bounding up, never knocked, slipped a "Sorry I missed you" card through the door - carefully - and was on his way back to his van when I ran out and collared him..."
I've seen this stunt pulled a few times (usually by Royalmail and Brutish Hash). Unfortunately for the staff concerned there's a full digital CCTV system covering the doors and gates. Mentioning that such footage would get interesting media attention seems to get remarkable results.