Program: 10390
Project: 10390
Buggy source:
@EventHandler public void entityDamage(EntityDamageEvent event){
  Map<String,Object> context=new HashMap<String,Object>();
  boolean isFatal=false;
  Entity entity=event.getEntity();
  String entityType=entity.getType().name();
  String cause=event.getCause().name();
  String determination;
  Player player=null;
  dNPC npc=null;
  if (CitizensAPI.getNPCRegistry().isNPC(entity)) {
    npc=DenizenAPI.getDenizenNPC(CitizensAPI.getNPCRegistry().getNPC(entity));
    context.put("String_Node_Str",npc);
    entityType="String_Node_Str";
  }
 else   if (entity instanceof Player) {
    player=(Player)entity;
    context.put("String_Node_Str",new dPlayer((Player)entity));
  }
 else {
    context.put("String_Node_Str",new dEntity(entity));
  }
  context.put("String_Node_Str",new Element(event.getDamage()));
  context.put("String_Node_Str",new Element(event.getCause().name()));
  if (entity instanceof LivingEntity) {
    if (event.getDamage() >= ((LivingEntity)entity).getHealth()) {
      isFatal=true;
    }
  }
  List<String> events=new ArrayList<String>();
  events.add("String_Node_Str");
  events.add("String_Node_Str" + cause);
  events.add(entityType + "String_Node_Str");
  events.add(entityType + "String_Node_Str" + cause);
  if (isFatal == true) {
    events.add("String_Node_Str");
    events.add("String_Node_Str" + cause);
    events.add(entityType + "String_Node_Str");
    events.add(entityType + "String_Node_Str" + cause);
  }
  if (event instanceof EntityDamageByEntityEvent) {
    EntityDamageByEntityEvent subEvent=(EntityDamageByEntityEvent)event;
    Player subPlayer=null;
    dNPC subNPC=null;
    Entity damager=subEvent.getDamager();
    String damagerType=damager.getType().name();
    if (CitizensAPI.getNPCRegistry().isNPC(damager)) {
      subNPC=DenizenAPI.getDenizenNPC(CitizensAPI.getNPCRegistry().getNPC(entity));
      context.put("String_Node_Str",DenizenAPI.getDenizenNPC(CitizensAPI.getNPCRegistry().getNPC(damager)));
      damagerType="String_Node_Str";
      if (npc == null)       npc=subNPC;
    }
 else     if (damager instanceof Player) {
      subPlayer=(Player)damager;
      context.put("String_Node_Str",new dPlayer((Player)damager));
      if (player == null)       player=subPlayer;
    }
 else {
      context.put("String_Node_Str",new dEntity(damager));
      if (damager instanceof Projectile) {
        if (((Projectile)damager).getShooter() != null)         context.put("String_Node_Str",new dEntity(((Projectile)damager).getShooter()));
 else         context.put("String_Node_Str",Element.valueOf("String_Node_Str"));
      }
    }
    events.add("String_Node_Str");
    events.add("String_Node_Str" + damagerType);
    events.add(entityType + "String_Node_Str");
    events.add(entityType + "String_Node_Str" + damagerType);
    List<String> subEvents=new ArrayList<String>();
    subEvents.add("String_Node_Str");
    subEvents.add("String_Node_Str" + entityType);
    subEvents.add(damagerType + "String_Node_Str");
    subEvents.add(damagerType + "String_Node_Str" + entityType);
    if (isFatal == true) {
      events.add("String_Node_Str");
      events.add("String_Node_Str" + damagerType);
      events.add(entityType + "String_Node_Str");
      events.add(entityType + "String_Node_Str" + damagerType);
      subEvents.add("String_Node_Str");
      subEvents.add("String_Node_Str" + entityType);
      subEvents.add(damagerType + "String_Node_Str");
      subEvents.add(damagerType + "String_Node_Str" + entityType);
    }
    determination=doEvents(subEvents,subNPC,subPlayer,context);
    if (determination.toUpperCase().startsWith("String_Node_Str"))     event.setCancelled(true);
 else     if (Argument.valueOf(determination).matchesPrimitive(aH.PrimitiveType.Double)) {
      event.setDamage(aH.getDoubleFrom(determination));
    }
  }
  determination=doEvents(events,npc,player,context);
  if (determination.toUpperCase().startsWith("String_Node_Str"))   event.setCancelled(true);
 else   if (Argument.valueOf(determination).matchesPrimitive(aH.PrimitiveType.Double)) {
    event.setDamage(aH.getDoubleFrom(determination));
  }
}

Fixed version (ground truth):
@EventHandler public void entityDamage(EntityDamageEvent event){
  Map<String,Object> context=new HashMap<String,Object>();
  boolean isFatal=false;
  dEntity entity=new dEntity(event.getEntity());
  String entityType=entity.getType();
  String cause=event.getCause().name();
  String determination;
  dPlayer player=null;
  dNPC npc=null;
  if (entity.isNPC()) {
    context.put("String_Node_Str",new dNPC(entity.getNPC()));
    entityType="String_Node_Str";
  }
 else   if (entity.isPlayer()) {
    player=new dPlayer(entity.getPlayer());
    context.put("String_Node_Str",new dPlayer(entity.getPlayer()));
  }
 else {
    context.put("String_Node_Str",entity);
  }
  context.put("String_Node_Str",new Element(event.getDamage()));
  context.put("String_Node_Str",new Element(event.getCause().name()));
  if (entity instanceof LivingEntity) {
    if (event.getDamage() >= ((LivingEntity)entity).getHealth()) {
      isFatal=true;
    }
  }
  List<String> events=new ArrayList<String>();
  events.add("String_Node_Str");
  events.add("String_Node_Str" + cause);
  events.add(entityType + "String_Node_Str");
  events.add(entityType + "String_Node_Str" + cause);
  if (isFatal == true) {
    events.add("String_Node_Str");
    events.add("String_Node_Str" + cause);
    events.add(entityType + "String_Node_Str");
    events.add(entityType + "String_Node_Str" + cause);
  }
  if (event instanceof EntityDamageByEntityEvent) {
    EntityDamageByEntityEvent subEvent=(EntityDamageByEntityEvent)event;
    dPlayer subPlayer=null;
    dNPC subNPC=null;
    dEntity damager=new dEntity(subEvent.getDamager());
    String damagerType=damager.getType();
    if (damager.isNPC()) {
      subNPC=new dNPC(entity.getNPC());
      context.put("String_Node_Str",new dNPC(damager.getNPC()));
      damagerType="String_Node_Str";
      if (npc == null)       npc=subNPC;
    }
 else     if (damager.isPlayer()) {
      subPlayer=new dPlayer(damager.getPlayer());
      context.put("String_Node_Str",new dPlayer((Player)damager));
      if (player == null)       player=subPlayer;
    }
 else {
      context.put("String_Node_Str",damager);
      if (damager instanceof Projectile) {
        if (((Projectile)damager).getShooter() != null)         context.put("String_Node_Str",new dEntity(((Projectile)damager).getShooter()));
 else         context.put("String_Node_Str",Element.valueOf("String_Node_Str"));
      }
    }
    events.add("String_Node_Str");
    events.add("String_Node_Str" + damagerType);
    events.add(entityType + "String_Node_Str");
    events.add(entityType + "String_Node_Str" + damagerType);
    List<String> subEvents=new ArrayList<String>();
    subEvents.add("String_Node_Str");
    subEvents.add("String_Node_Str" + entityType);
    subEvents.add(damagerType + "String_Node_Str");
    subEvents.add(damagerType + "String_Node_Str" + entityType);
    if (isFatal == true) {
      events.add("String_Node_Str");
      events.add("String_Node_Str" + damagerType);
      events.add(entityType + "String_Node_Str");
      events.add(entityType + "String_Node_Str" + damagerType);
      subEvents.add("String_Node_Str");
      subEvents.add("String_Node_Str" + entityType);
      subEvents.add(damagerType + "String_Node_Str");
      subEvents.add(damagerType + "String_Node_Str" + entityType);
    }
    determination=doEvents(subEvents,subNPC,subPlayer.getPlayerEntity(),context);
    if (determination.toUpperCase().startsWith("String_Node_Str"))     event.setCancelled(true);
 else     if (Argument.valueOf(determination).matchesPrimitive(aH.PrimitiveType.Double)) {
      event.setDamage(aH.getDoubleFrom(determination));
    }
  }
  determination=doEvents(events,npc,player.getPlayerEntity(),context);
  if (determination.toUpperCase().startsWith("String_Node_Str"))   event.setCancelled(true);
 else   if (Argument.valueOf(determination).matchesPrimitive(aH.PrimitiveType.Double)) {
    event.setDamage(aH.getDoubleFrom(determination));
  }
}