Program: 22232
Project: 22232
Buggy source:
@Override public void onPlayerPickupItem(EntityItemPickupEvent event,ItemStack armorStack,EntityEquipmentSlot slot){
  EntityPlayer player=(EntityPlayer)event.getEntityLiving();
  if (player.worldObj.isRemote) {
    return;
  }
  if (ChargableUtility.hasPower(player,10)) {
    ItemStack item=event.getItem().getEntityItem();
    if (item.hasTagCompound() && item.getTagCompound().hasKey("String_Node_Str")) {
      return;
    }
    boolean isCannable=OreDictHelper.mapHasItem(OreDictHelper.ingots,item.getItem()) || OreDictHelper.mapHasItem(OreDictHelper.gems,item.getItem()) || OreDictHelper.listHasItem(OreDictHelper.nuggets,item.getItem());
    if (!isCannable) {
      return;
    }
    int numCans=0;
    for (int i=0; i < player.inventory.getSizeInventory(); i++) {
      ItemStack stackInSlot=player.inventory.getStackInSlot(i);
      if (stackInSlot != null && stackInSlot.getItem() == ITEM_CANISTER) {
        numCans+=stackInSlot.stackSize;
      }
    }
    if (numCans >= item.stackSize) {
      if (!item.hasTagCompound()) {
        item.setTagCompound(new NBTTagCompound());
      }
      item.getTagCompound().setInteger("String_Node_Str",0);
      for (int i=0; i < item.stackSize; i++) {
        eiteam.esteemedinnovation.api.util.InventoryUtility.consumeInventoryItem(player,ITEM_CANISTER);
        player.inventoryContainer.detectAndSendChanges();
      }
    }
 else     if (numCans != 0) {
      item.stackSize-=numCans;
      event.getItem().setEntityItemStack(item);
      ItemStack item2=item.copy();
      item2.stackSize=numCans;
      if (!item2.hasTagCompound()) {
        item2.setTagCompound(new NBTTagCompound());
      }
      item2.getTagCompound().setInteger("String_Node_Str",0);
      for (int i=0; i < numCans; i++) {
        eiteam.esteemedinnovation.api.util.InventoryUtility.consumeInventoryItem(player,ITEM_CANISTER);
        player.inventoryContainer.detectAndSendChanges();
      }
    }
  }
}

Fixed version (ground truth):
@Override public void onPlayerPickupItem(EntityItemPickupEvent event,ItemStack armorStack,EntityEquipmentSlot slot){
  EntityPlayer player=(EntityPlayer)event.getEntityLiving();
  if (player.world.isRemote) {
    return;
  }
  if (ChargableUtility.hasPower(player,10)) {
    ItemStack item=event.getItem().getItem();
    if (item.hasTagCompound() && item.getTagCompound().hasKey("String_Node_Str")) {
      return;
    }
    boolean isCannable=OreDictHelper.mapHasItem(OreDictHelper.ingots,item.getItem()) || OreDictHelper.mapHasItem(OreDictHelper.gems,item.getItem()) || OreDictHelper.listHasItem(OreDictHelper.nuggets,item.getItem());
    if (!isCannable) {
      return;
    }
    int numCans=0;
    for (int i=0; i < player.inventory.getSizeInventory(); i++) {
      ItemStack stackInSlot=player.inventory.getStackInSlot(i);
      if (stackInSlot != null && stackInSlot.getItem() == ITEM_CANISTER) {
        numCans+=stackInSlot.getCount();
      }
    }
    if (numCans >= item.getCount()) {
      if (!item.hasTagCompound()) {
        item.setTagCompound(new NBTTagCompound());
      }
      item.getTagCompound().setInteger("String_Node_Str",0);
      for (int i=0; i < item.getCount(); i++) {
        eiteam.esteemedinnovation.api.util.InventoryUtility.consumeInventoryItem(player,ITEM_CANISTER);
        player.inventoryContainer.detectAndSendChanges();
      }
    }
 else     if (numCans != 0) {
      item.shrink(numCans);
      event.getItem().setItem(item);
      ItemStack item2=item.copy();
      item2.setCount(numCans);
      if (!item2.hasTagCompound()) {
        item2.setTagCompound(new NBTTagCompound());
      }
      item2.getTagCompound().setInteger("String_Node_Str",0);
      for (int i=0; i < numCans; i++) {
        eiteam.esteemedinnovation.api.util.InventoryUtility.consumeInventoryItem(player,ITEM_CANISTER);
        player.inventoryContainer.detectAndSendChanges();
      }
    }
  }
}