Of course, they could still have done things the right way - or easier yet, do them the right way the first time. This isn't rocket science where you have some unknown combination of factors that result in a problem - it was clearly spelled out in the law.
Well, that's one of those oversights that simply can't be fixed; I'm willing to bet whoever was responsible for not pointing this out in the legal department got fired.
FYI, any time you change the general design of a safety restraint (or add one) to a vehicle, NHTSA makes you go through the entire crash testing certification again, from zero.