Chester isn't Rydal father

When Rydal first met Chester, he saw the dream life. Money, style, seemingly happy, a beautiful & loving wife, and also the ability to con people out of their money better then Rydal was doing. Chester, while not trusting him upon their first meeting, saw a younger version of himself. As time went on, Chester's mistakes brought his whole world crashing down and ruined himself and those around him, so this ideal image Rydal had was destroyed.

"I'm sorry I disappointed you" is also an echo of earlier comments Chester made to Rydal regarding parents.
He said something to the effect that we expect so much of them and then, as we get older, they disappoint us.

After watching this film I came up with the theory that he actually was his dad which I thought was a very clever twist. I then did some research online and found out that this wasn't the case at all.
I kind of feel that the film would have been better if this was the case because of that twist. Being a swindler MacFarland faked his death at the beginning. It also explains why he got so upset when Rydal complained about his father.
I think the director has missed a trick here but it may be that he has been constrained by the novel.

I think that would have been a VERY interesting twist, but it wouldn't have made any sense. But there were some things that would make you think, like when Rydal was sitting there with that girl and she noticed him looking at them and commented how pretty that girl was, and he said something like "Oh no, I was looking at the man, he looks like someone's father I knew" or something to that extent. They were both con artists. And Chester was getting pissed when he was talking about his own father, like he was taking it personally.

I didn't read the book, but I doubt that was a plot point.