I agree it seems strange but I must admit I don't have any knowledge on how the structure works between ND and Sony. Ballard's claims seemed clear that Sony were the ones dealing with it and deciding to fire him though. I'd assume even if it weren't true he'd be aware of what the procedure was so that part must be accurate.
I have no idea, but if Sony was involved, something else must have been going on (maybe it's because it was a lead?)
But Sony's involvement is very odd.
Naughty Dog is a 350+ person company. They have their own communications team, their own HR team, their own recruiters, their own two Presidents, their own legal counsel, etc.
How did an issue between Naughty Dog and an employee escalate to a parent company?
Just to add contrast again, this would be the equivalent of Verizon getting involved in an AOL dispute, or AOL getting involved in a HuffPost dispute, or Tencent getting involved in a Riot Games dispute.
Sexual harassment is awful, but it's not massive enough to warrant escalation outside of a subsidiary.