This is an email I got from one of the individual investors of who frequent the blog before Lehman announced its record writedown. It appears as if he was onto something!

"I think Lehman may be an interesting bank to look into (even though I believe Bear Stearns is in the absolute worst position, Lehman is not much better off I think, while at the same time being perceived as having dodged excessive write-downs a-la Goldman Sachs). It starts with FAS 159 which you may be aware of. You can read how this has helped out the investment banks in the link below.
http://blogs.wsj.com/marketbeat/2007/09/21/great-moments-in-accounting/

Lehman has benefited the most on a relative and absolute basis thus far from FAS 159 accounting. Since they've filed their 10K recently we can update the total benefit they've booked as a result of a decline in their own credit worthiness for the liabilities they've elected to measure at fair value (FAS 159 allows companies to apply fair value to both their assets and LIABILITIES). From the 10K, on page 109 it states that "The estimated changes in the fair value of these liabilities were gains of approximately $1.3 billion, attributable to the widening of our credit spreads during fiscal year 2007." Lehman appears to have used $900 million of this gain to decrease the impact of write-downs (see table on page 49 of the LEH 10K, under "Valuation of debt liabilities"). For the year, Lehman booked write-downs of $1.9 billion total, however backing out FAS 159 gains would have substantially increased this amount. Again, looking at the write-down table on page 49 Lehman describes their gross and net write-down totals. From this we can back into how hedged Lehman is in each category of investment. The two primary categories to look at are there Residential mortgage-related and Commercial mortgage related positions. Looking at Residential, they booked a $4.7 billion gross write-down but only a $1.3 billion net write-down, implying that they are 72% hedged on their exposure to Residential Mortgage positions. Their commercial positions saw a $1.2 billion gross write-down, and a $900 million net write-down, suggesting they are only 25% hedged to their commercial positions.