Like Josh said, they had 65nm equipment 6 months before shipping. Who knows how much they mined and kept at that point

I think he said that it was 6 months between getting chips for 65nm and shipping, which seems about right given the timelines.
In a lot of ways, I think the Skype chat kind of vindicates BFL from some of the accusations of self-mining. The spinning and misrepresentation about deadlines is inexcusable (especially with regards to the tapeout of the 28nm chip), but from everything there it looks like these guys really could not get their products finalized and out the door in timely manner.