I think the story doesn't pass the red face test. The USPS has an internal tracking system the general public cannot see. One call into customer service, or show up at the mailing post office, and they can jump on the system and find out where the envelope fell off the radar. This is actually what they do when a trace is initiated. They take their tracked services pretty seriously, so traces generally find them quite fast - I have had lots of experience (unfortunately) with this.
Unlike what some believe here, a bank does not, and is not, obligated to immediately cancel a cashier's check and reissue. Been that way awhile now thanks to fraud. They can, and do regularly, keep money held hostage for their established time periods - you will find they have their policies written on this. YOU should show up to your bank and discuss the situation with the branch manager. Cashier's checks are not the same guaranteed funds they were once perceived as and you may have options there.
It really sounds like your acquaintance is down on his luck and robbing Peter to pay Paul and is jerking you around. Particularly jerking you around beyond established timetables under law to rescind a purchase, and practice for cashing of funds and their reversal... It's not unusual to purchase with an existing lien, but additional steps must be taken to protect yourself as a buyer. You're being put in a real jam, and your bill of sale doesn't give you as much strength here as you may think. Fundamentally, your buddy isn't the owner of that 5er. The lien holder, who has the title, is the owner.
Good luck, and I truly hope it works out for you!
