I'm not surprised by this. In fact prior to sitting down to look at HN I was reading 'the accidental billionaires' while (ahem) taking care of business. Of all the characters portrayed in the film (and book), Parker is the one played by the 'star'. It is him that is shown to have a lavish lifestyle of drinking and womanising. He is the protagonist to Eduardo, he is the one caught by the cops. Clearly the book and thus film is heavily slanted towards Eduardo's point of view - the others didn't contribute - so Parker probably got off the worst.

I've no idea of the level of fiction, but clearly his character must have a fair bit of it. And if it were me, I'd be making sure that level of doubt was clearly established in people's minds.