He's done immeasurable damage to his reputation and legacy
It could be repaired in time, but for the foreseeable he will be persona-non-grata at the club that made him famous
I don't know what made him think he could have ridden this one out. Sure, maybe he'd be out in the cold in the short term as part of Kenwright's revenge, but once new owners were in place he could have easily worked his way back in and would have retained the respect and appreciation of the fanbase
It's quite a tragic tale in all honesty
I always say that there are two types of football executive role a former great player can assume:
1. The Bobby Charlton role - a largely benign figurehead who personifies and safeguards the soul and glory of the club and acts as an ambassador by exercising soft power. See also Eusebio and Uwe Seeler.
2. The Karl-Heinz Rummenigge role - a political operator who draws on personal magnetism and prestige to influence and manipulate the power structures of football. See also Michel Platini.
The problem for most former players is they were never great enough as players to assume these roles - and if they were they are not smart enough to pick the right one or skilled enough to do it well (See Platini, again).
The best practitioners of this art never really put themselves directly in the firing line. Charlton, for example, was only ever a director holding moral authority rather than hard power. Rummenigge preferred to remain the power behind the throne at Bayern, build on international ties, and hold chairmanship of the European Club Association to keep pressure on UEFA. In that sense, they could always keep a safe distance from inevitable fallout.
Sharp was just a placeman with nothing to offer. He didn't have the moral authority that a Charlton had (our nearest equivalent would be somebody like Colin Harvey or Joe Royle), nor was he politically astute like Rummenigge. That was proven by his failure to resign at headlockgate. Had he done that, he would have immediately assumed the moral authority to become a politically relevant presence. He picked the wrong side and is now redundant. His personal reputation is in tatters and he will now have no "after-life" as a club functionary.