Tortured logic on this one.
Straightforward explanation is that, having read the cards on Trump winning the race, Comey is trying to keep himself out of jail.
Comey’s “protect Clinton” gambit lost, and he’s salvaging what he can of his position.
Yours is the most straight forward, least convoluted answer:
Comey sees "the hand writing on the wall": Trump is going to win in a landslide which precludes the Clinton Crime Family Syndicate and the utterly corrupt DNC & Soros from rigging the election in Hildabeast's favor. Consequently POTUS Trump will appoint a Special Prosecutor and FBI Director Comey, Deputy Director McCabe along with AG Lynch, Huma, Hildabeast, Rapist Bill and a host of others are ALL going to prison. This coupled with the fact that there is total rebellion and outright mutiny taking place against Comey within the rank and file agents of the FBI, along with the NYPD's threat to Comey that they would clandestinely leak the damn in evidence that they found if he didn't reopen the investigation; Comey had no choice but to do so.
Comey is no hero taking one for the Republic, he is a dirty cop, a sleeze bag who got caught and he is just in CASE mode.