Calling the report damning is quite the exaggeration. The IG concluded that Strzok and Page created the appearance of bias with their texts, but also says that he found no evidence that they acted on the apparent bias. He does think that their bias hurts the credibility of the FBI, though.

The only other issue the IG had was with Comey's public statements about the Clinton emails investigation. Even there he concludes that Comey wasn't acting out of political bias, and instead just somewhat mishandled an extremely unusual case.

I would hardly call those conclusions damning.