Depending on who the leading underwriters are they will be talking to either Lloyds Aviation or Airclaims, both organisations have highly qualified engineers on their staff.
If the insurers disallowed the claim because of tyre pressure then they can expect a court case to ensue and experts to be called who will say that tyre pressure had no influence on this accident.
Also, an engineer could stand up and say that prior to the flight commencing he reduced the tyre pressures