The tester from certification (on platform holder's side) may tell -or not- that found certain bug not listed in the console's TRC checklist of stuff needed to be certified. But that won't block the game from getting certification, because certification is to make sure the game doesn't break the console and follows certain standards for using stuff like gamepads, trophies, console user management, etc.
The platform holder's certification team doesn't need to find bugs or to block a game's certification because it has too much bugs (other than the super important specific ones included in the TRC like the game bricking the console or corrupting the HDD stuff) or if its performance sucks.