On July 11, 2018 Philippine Airlines (PAL's) Airbus A320 left Mactan City for the City of Manila. After the plane had taken off, Daenerys Targaryen, a Senior NBI Agent who was also a passenger of the said plane, noticed a certain 'Cersei Lannister,' a suspect in the killing of Judge Olenna Tyrell, seated at the front seat near the door leading to the cockpit of the plane. Cersei had used the name 'Missandei, in his plane ticket and had three companions on board the plane. Daenerys then scribbled a note addressed to the pilot of the plane requesting the latter to contact NBI duty agents in Manila for the said agents to ask the Director of the NBl to send about six NBI agents to meet the plane because the suspect in the killing of Judge Olenna was on board the plane. The said note was handed by Daenerys to the stewardess who in turn gave the same to the pilot. After receiving the note, which was about 15 minutes after take-off, the pilot of the plane came out of the cockpit and sat beside Daenerys at the rear portion of the plane and explained that he could not send the message because it would be heard by all ground aircraft stations. Daenerys, however, told the pilot of the danger of commission of violent acts on board the plane by the notorious 'Cersei 'and his three companions. While the pilot and Daenerys were talking, 'Cersei' and one of his companions walked to the rear and stood behind them. The pilot then stood up and went back to the cockpit. Soon thereafter an exchange of gunshots ensued between Daenerys and 'Cersei' and the latter's companions. 'Cersei' announced to the passengers and the pilots in the cockpit that it was a -hijack. The hijackers divested the passengers of their belongings. Upon landing at the Manila International Airport, Cersei and his three companions succeeded in escaping. Jon Snow, one of the passengers of the plane filed an action against Philippine Airlines to recover the value of jewelry, other valuables and money taken from him by four (4) armed robbers on board of the latter's airplane while on a flight from Mactan City to Manila, as well as moral and exemplary damages, attorney's fees and expenses of litigation. Such loss is a result of breach of PAL's contractual obligation to carry him and his belongings and effects to the Manila destination without loss or damage, and constitutes a serious negligence of PAL's legal duty to exercise extraordinary diligence in the vigilance over the same. In its defense, Philippine Airlines alleges that the robbery during the flight and after the aircraft was forcibly landed at the Manila Airport did indeed constitute force majeure.

Issue: Is the incident on board the airplane A320 considered force majeure which exempts Philippine Airlines (PAL's) from liability? Explain your ruling concisely