There might not be a personal consequence directly attached to Amazon employment, but this certainly has impact from a career standpoint.
Mentioning the manager could inhibit him from further employment elsewhere, because once the HR Depts of other companies' start to gather background information on him, they'll think he's a whiner fingerpointer. You cannot exclude a person from employment just for that, but they'll find another reason to not hire him.
It doesn't drive change at Amazon, but it saves him unnecessary risk.
Mentioning the manager could inhibit him from further employment elsewhere, because once the HR Depts of other companies' start to gather background information on him, they'll think he's a whiner fingerpointer. You cannot exclude a person from employment just for that, but they'll find another reason to not hire him.
It doesn't drive change at Amazon, but it saves him unnecessary risk.