"Steven P. McNicoll" wrote:
But it doesn't explain why anyone would consider the unauthorized
presence on a taxiway in the US to be a runway incursion because the
FAA definition of runway incursion has never included taxiways.

Probably because the FAA manages to contradict itself on what constitutes a
runway and a taxiway. Consider "Case 1" on page B-1 of the 2008 Runway
Safety Report:

http://www.faa.gov/airports/runway_s...RSReport08.pdf

"Although he is not on the runway, the aircraft's nose is across
the hold-short line, usually 175 feet from the runway.

A runway incursion has occurred since separation rules
require that a runway be clear of any obstacle before an
aircraft can land or take off on that runway."

So here we have an FAA document saying in the first sentence that example
aircraft B was _not_ on the runway. In fact it indicates aircraft B's nose
could be as far as 175 feet from the runway. But in the second sentence it
says a runway incursion happened anyway because aircraft B _was_ on the
runway! In order for me to make sense of those two sentences, either the
definition of what constitutes a runway has to change between them or the
definition has to contain a non-trivial conditional. If they said the
runway was that portion past the hold-short line then their discussion
wouldn't contradict itself (on the other hand, what would one then call 175
feet of pavement between the hold-short line and the runway proper in their
example other than a "taxiway?")

Based on the evidence so far, I have no confidence that you know (or the
FAA actually has) a consistent definition of "runway," "taxiway," or
"runway incursion." So if you could stop insulting others until you or they
collectively get your acts together, it would be appreciated. Otherwise you
come across (as you have put it) as a "wacko."