We can’t believe it
We heard you like cans, dawg, so we put a can inside of your can so you can open a can after you open a can. We’ve seen manufacturing errors, but this one seems downright impossible. We imagine that canned food makers don’t use metal detectors to search for, well, metal in the product, so there are probably more manufacturing errors like this.
We don’t know what it is about canned beans, but they probably the most hilarious type of canned food for sale. And double-canned beans sound twice as hysterical, if we do say so ourselves. But at the end of the day, the OP should be happy with what they got.