Yeah, known problem, might have even been posted here before.

Easy way to tell is to look at the "warning, cook to at least (blah blah) temp" disclaimer on the label. You won't see it on prime rib roasts, but you will on their tri-tip loins and smaller.

That's why I buy steaks from the local butcher when I can. Wife overrides me about once a month because she doesn't like ribeyes.