I did the same thing that you did, looking at all the available data in an attempt to date the shoot. Most of them, as you say, are dated in October, but I have one thumbnail of him in the light jacket that has the following information attached in the 'properties':

Created: 07/10/2003
Modified: 10/14/2003

Which only makes me wonder if the first number is really meant to be October 7 rather than the July 10 which is appears. And if so, why is the second number written out American fashion? It only makes it that much more confusing.

I'm relatively certain that they couldn't have been taken the day after C4, though. He looked considerably more robust for that con, plus he was clean shaven except for the sideburns and chin scruff, unlike the several days' growth that he's showing in these pics. Another clue is that I had some of these pics in my possession as of October 17, and I'm betting that the thumbnails are dated October 14 because that's either when I first grabbed them or perhaps when they were first uploaded to the internet, and it doesn't seem very likely that they could have been taken the 7th and have that be the case.

So, I guess it's still a mystery!