Program: 174586
Project: 174586
Buggy source:
@SubscribeEvent(priority=EventPriority.HIGHEST) public static void onLivingHurt(LivingHurtEvent event){
  if (!event.getEntityLiving().world.isRemote) {
    if (event.getSource().getTrueSource() instanceof EntityPlayer && !(event.getSource() instanceof LSCDamageSource) && !event.getSource().isFireDamage()) {
      EntityPlayer player=(EntityPlayer)event.getSource().getTrueSource();
      EntityLivingBase enemy=event.getEntityLiving();
      ItemStack weapon=player.getHeldItem(player.getActiveHand());
      PlayerInformation playerInfo=(PlayerInformation)player.getCapability(CapabilityPlayerInformation.PLAYER_INFORMATION,null);
      Stats stats=(Stats)player.getCapability(CapabilityPlayerStats.STATS,null);
      if (playerInfo != null && stats != null && weapon != ItemStack.EMPTY) {
        if (weapon.getItem() instanceof ItemSword) {
          playerMeleeAttack(event,player,enemy,weapon,playerInfo,stats);
        }
 else         if (weapon.getItem() instanceof ItemBow && event.getSource().getImmediateSource() instanceof EntityArrow) {
          playerMeleeAttack(event,player,enemy,weapon,playerInfo,stats);
        }
      }
    }
    if (event.getEntityLiving() instanceof EntityPlayer && (event.getSource().getTrueSource() instanceof EntityLivingBase || (event.getSource() instanceof LSCDamageSource) || event.getSource().isFireDamage())) {
      EntityPlayer player=(EntityPlayer)event.getEntityLiving();
      EntityLivingBase enemy=(EntityLivingBase)event.getSource().getTrueSource();
      PlayerInformation playerInfo=(PlayerInformation)player.getCapability(CapabilityPlayerInformation.PLAYER_INFORMATION,null);
      Stats stats=(Stats)player.getCapability(CapabilityPlayerStats.STATS,null);
      if (playerInfo != null && stats != null) {
        LootSlashConquer.LOGGER.info("String_Node_Str" + event.getSource().damageType);
        if ((event.getSource() instanceof LSCDamageSource || event.getSource().isFireDamage()) || (event.getSource() instanceof LSCDamageSource && ((LSCDamageSource)event.getSource()).isChainedDamage())) {
          double damage=DamageUtils.applyElementalResistance(event.getAmount(),(LSCDamageSource)event.getSource(),player);
          event.setAmount((float)damage);
        }
 else {
          double damage=DamageUtils.applyArmorReductions(event.getAmount(),player,playerInfo);
          event.setAmount((float)damage);
          for (          ItemStack stack : player.getArmorInventoryList()) {
            NBTTagCompound nbt=NBTHelper.loadStackNBT(stack);
            if (Attribute.DURABLE.hasAttribute(nbt) && Math.random() < Attribute.DURABLE.getAmount(nbt))             stack.setItemDamage(stack.getItemDamage() + 1);
          }
        }
      }
    }
    if (event.getSource().getTrueSource() instanceof EntityPlayer && !(event.getEntityLiving() instanceof EntityPlayer)) {
    }
  }
}

Fixed version (ground truth):
@SubscribeEvent(priority=EventPriority.HIGHEST) public static void onLivingHurt(LivingHurtEvent event){
  if (!event.getEntityLiving().world.isRemote) {
    if (event.getSource().getTrueSource() instanceof EntityPlayer && !(event.getSource() instanceof LSCDamageSource) && !event.getSource().isFireDamage()) {
      EntityPlayer player=(EntityPlayer)event.getSource().getTrueSource();
      EntityLivingBase enemy=event.getEntityLiving();
      ItemStack weapon=player.getHeldItem(player.getActiveHand());
      PlayerInformation playerInfo=(PlayerInformation)player.getCapability(CapabilityPlayerInformation.PLAYER_INFORMATION,null);
      Stats stats=(Stats)player.getCapability(CapabilityPlayerStats.STATS,null);
      if (playerInfo != null && stats != null && weapon != ItemStack.EMPTY) {
        if (weapon.getItem() instanceof ItemSword) {
          playerMeleeAttack(event,player,enemy,weapon,playerInfo,stats);
        }
 else         if (weapon.getItem() instanceof ItemBow && event.getSource().getImmediateSource() instanceof EntityArrow) {
          playerMeleeAttack(event,player,enemy,weapon,playerInfo,stats);
        }
      }
    }
    if (event.getEntityLiving() instanceof EntityPlayer && (event.getSource().getTrueSource() instanceof EntityLivingBase || (event.getSource() instanceof LSCDamageSource) || event.getSource().isFireDamage())) {
      EntityPlayer player=(EntityPlayer)event.getEntityLiving();
      PlayerInformation playerInfo=(PlayerInformation)player.getCapability(CapabilityPlayerInformation.PLAYER_INFORMATION,null);
      Stats stats=(Stats)player.getCapability(CapabilityPlayerStats.STATS,null);
      if (playerInfo != null && stats != null) {
        LootSlashConquer.LOGGER.info("String_Node_Str" + event.getSource().damageType);
        if ((event.getSource() instanceof LSCDamageSource || event.getSource().isFireDamage()) || (event.getSource() instanceof LSCDamageSource && ((LSCDamageSource)event.getSource()).isChainedDamage())) {
          double damage=DamageUtils.applyElementalResistance(event.getAmount(),(LSCDamageSource)event.getSource(),player);
          event.setAmount((float)damage);
        }
 else {
          double damage=DamageUtils.applyArmorReductions(event.getAmount(),player,playerInfo);
          event.setAmount((float)damage);
          for (          ItemStack stack : player.getArmorInventoryList()) {
            NBTTagCompound nbt=NBTHelper.loadStackNBT(stack);
            if (Attribute.DURABLE.hasAttribute(nbt) && Math.random() < Attribute.DURABLE.getAmount(nbt))             stack.setItemDamage(stack.getItemDamage() + 1);
          }
        }
      }
    }
    if (event.getSource().getTrueSource() instanceof EntityPlayer && !(event.getEntityLiving() instanceof EntityPlayer)) {
    }
  }
}