Both were always creation engine. They were lambasted and memed on a few times due to how shit and dated it is.

The selling outside of areas where PSN is available, is on the publisher, which is in this case Sony.

It is my laymen understanding they are the ones that control the Steam listing that allowed it to be sold everywhere in the first place. If this is the case, then Sony opened themselves up to a shit ton of liability and blame on that part.

I'm not alleviating Arrowhead of their issue in the matter, especially after they were warned in February that this issue in particular was going to be a shit show.