Its OK for a police officer to tell a shop security guard about what police procedures are, what police action will follow and what the law is surrounding his actions. I have no problem with that.

I would have no problem with that either, but he was literally saying if the shop security didn't do what he wanted them to do, their reports would get NFA'd. So in other words, if they want their reports to actually go anywhere, they have to do their job the way he (an outsider) asked them to.

Would you still feel the same if the roles were reversed? You don't deal with a suspected shoplifter the way the store would like, so they say "If you don't do things this way, then we're not going to share CCTV with you again". And imagine that they have CCTV covering a regular hotspot for crime and you often ask to have a look at their tapes on a weekly basis. Is it still fair for the shop to "tell you what their policies are, and what action will follow" if you don't do your job the way they ask?