I like this story:
My favourite/most annoying thing caught on camera was two men in high vis jackets wheeling a full 12ft flower display from directly in front of the Retail Unit, out of the building (service station) and into their van while two Retail staff chatted 3 foot away. What made it worse was that one of the cleaners even picked up a couple of missed flowers and took them to the guys who were loading it all on their van. If only YouTube had been around then, it would have been a massive hit !
It shows that people tend to trust others in uniform, as above the fact that they were were high-visibilty jackets there was an assumption on retail staffs behalf that the thieves must have been from HeadOffice/Merchandiser or some other genuine reason to be there.
Two simple counter-steps: