You could still take the fat salary until they found out it's not working (because, of course, it cannot possibly work). If they decided the code base is too crufty (instead of deeming you incompetent) you could still keep the fat salary and land in another realm of the company. Unfortunately for you, the odds of them deciding the codebase is too crufty (and, therefore, that the very senior exec sitting on it managed its aging poorly) are not good.
