Treasury was wrong in its assertion that HERA, in an amendment of the Charter Act, granted it authority to purchase MBSs from Wall Street on the secondary market, in order to allow them to lock in the huge rally in price when the interest rates plummeted.
More trickery and evidence of attempt to twist the Charter Act, concealing the reality of a UST backup of FnF to finance their operations (MBSs in the TBA market or SPS), replica of the one since the Charter's inception at rates similar to Treasuries, that is the one we use in a final resolution (0.5% spread over Treasuries. A weighted-average 1.8% cumulative dividend on the SPS).
Explained in these two tweets: