Section 20. If the carrier proves that the damages was caused or contributed to by the negligence or other wrong

20. (1) The carrier is not liable if he proves that he and his agents have taken all necessary measures to avoid the damage or that it was impossible for him or them to take such measures. (2) In the carriage of goods and luggage the carrier is not liable if he proves that the damage was occasioned by negligent pilotage or negligence in the handling of the aircraft or in navigation and that, in all other respects, he and his agents have taken all necessary measures to avoid the damage. 20. The carrier is not liable if he proves that he and his servants or agents have taken all necessary measures to avoid the damage or that it was impossible for him or them to take such measures. 20. If the carrier proves that the damages was caused or contributed to by the negligence or other wrongful act or omission of the person claiming compensation, or the person from whom he or she derives his or her rights, the carrier shall be wholly or partly exonerated from its liability to the claimant to the extent that such negligence or wrongful act or omission caused or contributed to the damage. When by reason of death or injury of a passenger compensation is claimed by a person other than the passenger, the carrier shall likewise be wholly or partly exonerated from its liability to the extent that it proves that the damage was caused or contributed to by the negligence or other wrongful act or omission of that passenger. This rule applies to all the liability provisions of these rules, including sub-rule (1) of rule 21.