Is ‘force majeure’ as applied by ACNL the same as ‘justification’ applied by the ILT?

No, ‘justification’ applied by the ILT is a separate and independent policy solely used for enforcement on misuse of slots. The assessment of justification by ILT is based on the (Dutch) General Administrative Law Act, see article 4 of the Policy Rule. Airport Coordination Netherlands (ACNL) receives copies of all decisions made by ILT regarding slot misuse enforcement.