Seems like someone made an account pretending to be Hoffman's girlfriend. In the article it talks about accounts being made and deactivated. The way technology and social media is, it's pretty easy to "catfish" as someone else.
I'd wait until there's more done in the investigation before making such a quick judgement call on a couple. You would think if this was true, there would be HUGE rifts within the Ottawa locker room or at least between Hoffman and Karlsson. The Canadian media would've jumped on it a lot sooner.
I'm not saying otherwise. Even assuming the worst - that Hoffman's girlfriend did what's being alleged - that shouldn't be held against Hoffman if he had no role in it.