wow. WOW. That guy is just... awesome.
but he still owes you the FULL amount. regardless of whether or not he "doesn't like customs". Wtf. That's not your problem.
And plus... it was most likely customs that wrote "firearm parts" on the package as that was the exact term that customs gave to me. As an importer, he HAS to know that customs reserves the right to re-classify goods if they deem it necessary for duties and such.
And plus, yes, he CAN tell canada post that he was carrying firearms parts. The only thing that's prohibited for them to transport are goods that customs claims are prohibited... which general parts ARE NOT prohibited.