This topic would receive more attention if posted in the general forum since it has nothing to do with installing or running NWN. If you do, edit your original post to point there.
Regardless, have never heard of this "bug" before (for the stock game with v1.69) but can easily be tested with any trainer just by viewing the combat log. Custom content applications are capable of modifying the base algorithms to act however they like so unless the particular sample environment where this is supposedly occurring is specified any speculation as to its validity is moot.