How do you figure it is nothing to do with Honorcoin when the Honorcoin website specifically asked for the Bitcointalk forum user name and for an email and a password?
Of course the 'game' would have been sent from a zero post account, do you think Honorcoin would advertise that they were spamming forum users with this?
So they try out the passwords they have been given on the forum and, when they work, they get to log in to other people's accounts. Otherwise they send a few 'games' out for testing to some of the other registered user names they have. They wouldn't send it to everyone because, again, that would make it pretty clear where it originated from.
why use the same email and password in the first place? and the purpose of inserting forum id was to allocate free coins at least that was the reason behind it. If in fact they used it as a phishing scam well no ones really to know the wiser as of yet, unless you have physical proof of this action taking place IE , ip address's and logs of traffic behind it.