Truth in advertising is something that needs to be taken with a grain of salt. Joe's only has to has real crab legs in their commercial. There is nothing to say that they bucket isn't filled with ice almost up to the top and the crab legs put on there at the very last second.
It isn't false avdertising since you got what they advertised. You ordered king crab and that is what you got, not a bucket of french fries.