Are you saying that they should have looked the other way because the person that told them their employee was doing illegal shit was a bad person? Does that somehow make the behavior less true or more acceptable? There is no way that Nintendo could have fired her and not be perceived to "mishandle" it by these people standards. They handled it perfectly. Fired her, gave a simple ambiguous reason and that was all that was needed. They could have mishandled it in so many ways. They could have simply stated "she engaged in illegal behavior that is unbecoming for a Nintendo employee."
People bitching about how Nintendo dealt with this, I'd love to hear their alternatives. How are you going to explain to your shareholders that you knew your Public Relations employee advocated CP on twitter and was turning tricks in her time off and you decided to keep her on because, you know someone would get their feelings hurt or because you didn't like the person who proved to you that they were doing it?
Also, Nintendo stated she was not fired for her views, but for having a second job (Which they were kind enough to not mention was an illegal job). There's not really any proof that it was GG that outed her escort stuff to Nintendo. Not saying it's not possible, it just seems giving these dolts too much credit. It's more likely that when she said "I got fired for having a second job that I had taken under a fake name with no tracebacks to me" that was what people's radars going and then they found it out. I just don't see gg being smart enough to do that.