Slow roasting turkey for 20 hours. 300 at 1 hour to kill parasites. 8 hours at 175 degree. Oven accidentally turned off after 8 hours. Off for 6 hours. Can it be saved? Is it safe?
No, absolutely not. It needs to be discarded.
Sadly, I'd say it's achieved the bio-hazard stage, only useful as a weapon.
(Full disclosure: Question Authority is in my DNA.)
Over 50+ years, I have taken many many 'risks' re: the 'safety' of a certain item, as declared by careful conservative cooks.
That said, IF the turkey was injected with a saline solution by the food co., or if you brined it before cooking it, I think it could handle the mistake/delay. But if not, i would trash it and say 'we all make mistakes' and move on to something else.