Since it is native code we can’t see exactly what it’s checking, it may be a typo and it’s checking the IsPlayerPawn function on the pawn instead of bisplayer, or it could be casting from the pawn to it’s controller.
The only other thing I can think of off the top of my head is perhaps me using UDKbot instead of aicontroller might affect things.
Could you post your player pawn and controller?
EDIT: You can also verify the eyepoint is correct by adding the following to your tick event:
local vector ViewLocation;
local rotator ViewRot;
DrawDebugLine( ViewLocation, ViewLocation+200*normal(vector(viewrot)), 0, 255, 0, false);
I made a mistake in the GetPlayerViewPoint, instead of Pawn.Rotation it should just be Rotation. This only affects the pitch of the rotation, however so it shouldn’t damage seeplayer.