It's now part of "ancHNt history" (nickb hasn't posted for 6+ years). I did recall some discussion about nickb = pg, but don't think I had seen the 'smoking gun'. Noting how Reddit was started, I'm neither surprised nor concerned if there was such an account in the early days (either by pg or by the yc partners).
[Edit] Dammit. Now I've read Alex3917's response, I wish I'd done the accurate calculations on that "Smoking Gun" link to note it was posted on 1 April, 2008.