2008 - the mortgage payment of 55K was AFTER TAX. So no need to gross up Tax.
2011 - had no tax implications, as far as I can see.
after tax salary of 475K which equals living expenses of 250K + 225 K Payment on mortgage.
So no tax adjustment there.
2010 - Elisa Lima case -> 140 K Pre-tax salary, 96K Living expenses (after tax), tax rate = 25% so need to gross up the living expenses - since they ask for a pre-tax nominal rate of return.
140 - 96/(1-0.25) = 12 K which they tell you elsewhere is the TDA payment.