The Problem is Comey established a pattern of breaking his NDA and then admitting that he used his friends are proxies to leak to the press. He can claim the earlier leak was an innocent mistake at a dinner party with friends, but his admitted willful breaking of the NDA makes it very unlikely to have been an accident.

In the end, however, it does seem to confirm that this dinner event did occur, reinforcing Trump's character

The event yes, but not the content. With Comey's credibility ruined by lying under oath and his bizarre expiation of why he used a proxy to leak his the document of a conservation that he wrote up after the fact, becomes little more than fantasy outside of people who hate Trump. Comey destroyed his own credibility and probably ruined any chance of nailing Trump on obstruction of justice in the process.

I find it really amazing that anyone put any faith in Comey. The guy shit in the bed on Hillary email server last year and what happened yesterday was more of the same stupid Comey we'd seen previously.