The Wallace line demarcates biogeographical continents, which to a large extent coincide with the geological continents. On those grounds, East Timor is not a part of Asia. On the other hand, it seems that geopolitically East Timor is considered a part of Asia.
There are two problems I see with your position.
Firstly, Oceania is a geopolitical continent, not a biogeographic or geological one. From the geopolitical point of view, East Timor is in Asia. From any other point of view, Oceania doesn't exist. Either way, East Timor is not a part of Oceania.
Secondly, reputable sources have been presented, which state straight out that East Timor is in Asia. They may not state their criteria, but they are unambiguous in their position. You, on the other hand, are unable to present any sources, and are relying entirely upon reasoning. I salute your reasoning, but the fact is the sources win. The CIA and the UN are considered more reliable that your good self, no matter how ingenious your rationale. Wikipedia has a long-standing verifiability policy that states "The threshold for inclusion in Wikipedia is verifiability, not truth."
Hesperian