I mean I call plenty of things "so-and-so's reason" for something, even if they're not the originator of the idea but just the person I and whomever I'm talking

I mean I call plenty of things "so-and-so's reason" for something, even if they're not the originator of the idea but just the person I and whomever I'm talking with happen to know about it from. This seems like a silly linguistic nitpick to die on.