Undertoad, I don't think your reasoning has as much to do with the number of dimensions as it does the fact that up and down are absolute, while left and right are relative. If both pilots thought, "I'd dive and turn north", they'd be screwed too.
Sure, more dimensions means more combinations, but deciding <i>not</i> to turn right or left <i>is</i> a decision. For each dimension (side-to-side and up-and down -- you don't really have a decision whether to keep going forward

), if you count 1) going one way, 2) going the other way, and 3) doing nothing, then doing nothing has just as good a chance for survival as the other two. (Statistically speaking... of course this ignores the human behavior aspect).