Yes indeed they did file the claim but never even mentioned the guarantee which is noted on the prospectus. BNYM should have enforced that guarantee and they did not.
IMHO, this is where they have failed to uphold their fiduciary duty.
I could of course be wrong as I am no expert. The problem is to prove that the trustee omitted to enforce the guarantee puposely to profit from this. I am not sure if BNYM held any senior debt from LBHI at the time they filed the claim for the CT holders with the bankruptcy court.