Posted By:
warshawlawAll of the grading services have small print disclaimers in their submittal paperwork or elsewhere that disavow any responsibility for their flubs. Now, if you have a high profile buyer (e.g., Keith Olbermann) or a valuable enough card (e.g., a Ruth rookie) that litigation will follow on a refusal to make good, the companies will deviate from their norm and pay you off to go away.
The sole exception that I am aware of to this is GAI, which has an express buy-back policy insured by Lloyd's of London.