Honestly, I think anyone saying "Clinton didn't lose because of X, she lost because of Y" is oversimplifying things to a useless degree. There are a whole host of reasons why she lost, some of which were out of her control and some of which definitely were not, and it's disingenuous to try and blame a single one to the exclusion of all others.
That being said, she lost by such a narrow margin that it IS entirely possible to point to several of the factors that were out of her control and say that if not for any one of them, she might have won.