What deadline's conflicted? PD's last (full) PS2 title, GT4, was released in early 2005. The PS3 was released in late 2006. And it wasn't until late in 2010 that GT5 was released. Four years into the PS3's life cycle. I wasn't a PS1/PS2 owner and I didn't own any previous GT titles save Prologue. But GT fans and certainly people on GTP were clamoring for GT5 for YEARS. Imagine if you could go back in time to 2007 or 2008 and take a poll, ask how many people expected it would be close to 2011 before GT5 was on store shelves. I don't think ANYBODY would have imagined it would be that long. Empires have been created and fallen in less time.
The only politics I can imagine taking place are Sony finally giving PD an ultimatum that the game HAD to be on store shelves for Christmas 2010, full stop. Sony is the publisher. Although PD and Sony, share a special relationship, certainly so with Kazunori being on Sony's board, in the end, the developer is answerable to the publisher. It's simple business. Sony is footing the bill. How long were they going to fund development without turning a profit?
If you look at statements Kazunori made back in 2008(?), he was alluding that GT5 would be out soon. Does soon really mean 2 years? Whether it was because of GTPSP or waffling by Sony over what features they wanted, or the possibility that Mr. Yamauchi is a great visionary but was simply not able to effectively manage his great project within the time constraints given, we'll never know for sure. But the fact remains, the game which was released in the box last November, is not the game PD intended to ship. And for whatever reason, it was because PD couldn't finish it before the deadline. That is clear.