[kafkaesq]

How are loss prevention supposed to deal with it?

In the normal, pragmatic way: wait until you actually see them put the opened drink behind something else on the shelf. Which, not all the time but often enough, you surely will. If they're drinking it out in the open -- in the line at the register, say? Most likely they're going to pay for it.

Certain people will go so low at the expense of others, it makes for an unworkable culture.

By the same token, treating people as if they're already "low" (by not giving them the benefit of the doubt for an opening a $0.98 bottle of iced tea before paying) makes for an unworkable culture, also.