That's exactly why, really. Why use your own resources to even bother to re-work 90s technology? You have a guy who reversed engineered consoles for a living for the companies he worked for. Sony most likely had records of which devs had their dev kits, as to recall them. So, I doubt Sony called John Carlsen directly and said, 'Sup' dude? Yo, so, we want you to make a playstation in a controller for us, ok? Your skills are highly desired to us because we know who you are'? No, I imagine they reached out to companies who had done work for them with no dev kits. Find someone who was already familiar with simplifying their work and try to recruit those people to bring on board for a project.
It seems easier to me than having to spread out their internal team and snare their current projects down, only to have to break down and simplify the very stuff that was already done in the 90s. I don't think JC was the only guy on the project, I think he was a little guy who was brought into it, hence 'senior staff' and not 'Lead'. His past experience of having to work on Iguana's dev kit because they couldn't afford one paid off. In his case, he hit the lottery job wise.
I'm not arguing his Linkedin is padded. Honestly in the field he's in, it has to be. I just don't think he's bullshitting about being on a team that made a small playstation in 2010 for BRIC ~