Depends on what the legal ramifications are.
When I buy a new car, I expect it to fall within emissions and safety standards. Hell, I can't even request the thing doesn't drive around in the daytime without the headlights running (ARG hateses them); I can't get the back windows to roll all the way down because some irresponsible parent let their kids climb out while driving on the highway... ...degrade into rant about cars...
Although, in the countries I know of with accessibility laws, the client (the one who owns the web site) is the one held legally responsible if their site is inaccessible; they are the ones sued by Getty and Corbis if their developer used unpaid images; they are the ones given the letter if their developer uses text plagarised from somewhere.
That might mean the developer is required to be informed themselves, must inform the client, and are held responsible unless they have some signed waiver where the client claims all responsibility.
Is there a precedent anywhere where the client successfully put the blame over to the developer/developing company?