I was actually thinking of something rather different, but you have a point: if there were a lot of routes going nowhere, this one would not seem unusual... except for the fact that Zaharie apparently repeatedly came back to it, advancing it in steps to the point of fuel exhaustion. That seems very significant to me, assuming it is not a forgery or a misinterpretation of the data.

I was thinking that there might be evidence that Zaharie considered what Irving claims (mistakenly, I believe) was the only plausible course if Zaharie wanted to disappear: eastwards across the South China Sea.