The second fact is that, as soon as Peter Todd created his account on Bitcoin Talk, he posted a message within less than a minute, saying he wanted to buy an invitation to the social network Diaspora. This shows that his primary reason for creating the account was clearly to get an invitation, not to use the account after supposedly stopping to post as Satoshi Nakamoto.
Discussion
As for the message HBO focused on, if you consider that by that time Peter Todd already understood how Bitcoin transactions worked—after all, it was almost two years since the network's launch, and many people, including him, were familiar with the technology—there's nothing surprising about him reading Satoshi Nakamoto’s last post about transaction fees and simply adding his own thoughts on how he understood it. Moreover, it's clear that his message was not in Satoshi Nakamoto's style at all.
There’s another subtle point to consider. He returned to the forum a year and a half later and wrote that he was a Bitcoin user, offering the forum readers proof by saying, "Look, I have a message here." At that time, he only had two posts. The first was about buying an invitation to a social network for $2. The second was the Bitcoin transaction post, which HBO uses as their main argument. Now, what do you think he meant when he called himself a Bitcoin user and invited people to check? He clearly wasn’t referring to that first message about buying an invitation for $2—that has nothing to do with being a Bitcoin user. Most likely, he was pointing to the post where he discusses how changing the transaction fee affects inputs and outputs. And if we assume he was Satoshi Nakamoto, then how foolish would it be to come back to the forum under his real name, Peter Todd, and mention that he had posted about Bitcoin as Satoshi Nakamoto? It’s simply absurd!
Watch it again and look at how much he thinks about game theory. It doesn't seem far fetched at all to think that he would be worrying about people connecting those dots and trying to get ahead of it.
That kid can't be Satoshi, he isn't that smart after all.