especially if it's on the record, under oath
However, the median result is almost certainly "close to impossible" for most institutions if that's the only grievance. "Written to mislead" is going to be really hard to litigate, since academics are (a) often wrong, (b) theoretically capable of changing their minds, and thus (c) can always hide behind the fig leaf of "that was my educated opinion at the time."
At the end of the day, tenure is a morally neutral policy - it protects reformers and scoundrels alike, provided they abide by the relevant bylaws. (e.g., haven't broken state/federal laws, haven't falsified research, etc.)
