If he testified that he intended to provide for her care for the next 51 years then he is precluded from asserting that it was ever her intention to end her life by unnatural means. i.e., To his knowledge he had every expectation of discharging this obligation and needed funds to enable him to do so. It certainly would have been inconvenient for him to assert what he later claimed were her wishes to be disconnected since to do so would likely have reduced the amount of any potential award.
If his attorney didn't hammer this home then he needs to be disbarred. If the Judge was told this and ignored it, he needs hanging!