@ Duion : You are right to suggest this. I totally did try that as well yet the problem persisted.
@ marauder2k9 : It's a good idea, and something I hadn't thought to check, but looking over it all I've got the global variables...
$Game::defaultPlayerClass = "AIPlayer";
$Game::defaultPlayerDatablock = "AIPlayer";
...and spawning in using the same Sim::spawnObject() consolefunction:
%player = spawnObject($Game::defaultPlayerClass, $Game::defaultPlayerDatablock);
@ Happenstance : I found the static variables enherited from Player, so ended up changing those in player.cpp to 1. The visual effect of this is the spin occurs immediately and is much more noticeable. If someone's trying to replicate this that'll likely do the trick =). Setting these values to 1 I don't have to wait for the AIPlayer to be rotating while an early loading hitch occurs to produce the bug, the AIPlayer will display the unwanted behavior immediately. However, it does allow for a good look at it. With the warping disabled, it is easy to see that the issue isn't happening if the AIPlayer is walking on a straight forward vector but interpolates incorrectly as soon as a rotation occurs.
Speaking of looking at it, I will get a capture of this and post it up here as soon as I can so folks can see it.
Thanks for the help on this everyone, it's been a rough haul and since this particular bug has persisted since early in the game's development I figured it did warrant a bit of scrutiny.