I've flown in and out of the Philippines a lot. The airlines use an IATA database which tells them that you will only receive a visa for 21 days, and that they will deny boarding without it.
I've been asked for onward tickets with Asiana, Cathay and Singapore Airlines, in addition to Cebu Pacific in HK. I only once got asked by KLM. Asiana and Cathay were the strictest.
Generally its luck as to whether their system flags up to ask you or not, but if your unlucky you WILL be denied boarding.
This is even the case despite husband being able to get balakbayan visas and the possibility of getting extensions on arrival. When I was flying with Asiana, I lied and showed them my seamen discharge book, and said I'd be joining a ship in Manila so wouldn't need an onward ticket, and that took a lot of explaining. Think i was very close to having to pay for another ticket.
An easy route out is to book a ticket out of Clark to Kota Kinabalu (cost around 20-30 pounds) or get a fully refundable ticket and cancel it afterwards.
