The stack part should be the same as my backup version so let me check 
---------- Post added at 09:15 PM ---------- Previous post was at 09:13 PM ----------
Code:
//Hit based abilities
public OnWar3EventPostHurt(victim,attacker,dmg)
{
//Better order:
//Confirm valid trigger
if(victim>0&&attacker>0&&victim!=attacker)
{
//Confirm that it is for this race
new race_attacker=War3_GetRace(attacker);
if(race_attacker==thisRaceID)
{
//abilities below
//Blades
new knife_level=skill_level_knife[attacker];
if(knife_level>0 && !Hexed(attacker,false) && !W3HasImmunity(victim,Immunity_Skills) && Math_GetRandomFloat( 0.0, 1.0 ) <= knife_chance[knife_level])
{
Yep I do not see a damage stack prevention check in there anywhere. I will update this race when I can with a fix for this and a code restoration. All races that are considered code restored will have a note in their change log when they gain this status.
Great job locating that bug!