I'm thinking it has to do with link widths. FS can only guide AI properly as long as AI is on something, the links. If there's a curve in the taxiway, such as near 25R, AI may move slightly to the left or right of the taxiway centerline (link), that itself shouldn't be a problem, unless the link is as narrow in KLAS's Afcad, to suppress the hold short node markers.
What happened above, was that once the links were deleted and redrawn, they were presumably redrawn at a normal width, 100ft or whatever.
IMHO.