Wonder how one would defend themselves if someone took something to clearance, swapped the barcode and then another person bought the item thinking it was in clearance? If it sat there for awhile, there may not be video.
I know someone who did that and was proud of it - one person swapped the discount tags so they would only be guilty of some sort of mischief and not theft if caught. The other one entered the store a half hour later and successfully bought the high-priced items in self checkout. Sadly, it was a distant (but not distant enough) relative. I will never trust him again.