The boxed-in cachet on card the reverse is explanatory.  The card is dated April 11 and the MANILA postmark is on top of the of the upper right corner of the boxed-in cachet. I interpret these two facts as a sign that postal authorities had prior knowledge of the flight but perhaps did not have the foresight to document it.

The first official flown cover of the Philippines is the 1919 Ruth Law demonstration flight around Manila. Authority was made by the Bureau of Posts for the flight to carry mail  primarily due to the sponsorship of the Aero Club of the Philippines, a "private" organization. With respect to the Tom Gunn flight, I strongly believe that this should be Philippines #1. Okay, there is no known PO authority for the flight to carry mail. In 1914, Philippine aviation was at its infant stage. It is only understandable that nobody, not even the PO, came out with the idea to have the flight and the mail it carried documented. I will also assume that in 1914 no aero club existed in the Philippines.

There is no doubt that the bible of aerophilatelists is the AAMC. With this in mind, there is one fact that cannot be disputed: it is a man made listing and therefore subject to human shortcomings. For the AAMC Philippine section, not all listed flights were made with prior knowledge and / or authority. Likewise numerous unrecorded flights, both for the USPI and RP periods, have surfaced in the recent years -- flights that should have been listed but were not. 

I am again reminded of the 1931 Chichester Masbate to Manila unlisted flight. It failed to make the list because the cover to Bruggmann was not delivered. The stop at Masbate was due to emergency reasons and therefore PO authorities in Manila were not aware of it.  The only person that was aware of this flight was the Masbate postmaster, surely informed by Chichester as he wanted to fully document his round the world flight.

Twenty Masbate to Manila covers was sent by the Masbate PM  to the Director of Posts in Manila but no one knew about this until it was discovered by David Chiong in mid 1990. The so called icing on the cake to my reasoning is this: although only one cover exist of the Tom Gunn and Chichester Masbate to Manila flights, it is beyond doubt that they were flown. If we think with a brain the size of an ant, then we might as well say that both unrecorded flights never happened at all.