I think there's a bit of arrogance on both sides.  Just shipping some random guy $5k worth of btc is...risky, to say the least.  I also don't understand this whole "Bulgarian" thing.  And "partner".  That just seems shady to me and a cop out to try and pass blame elsewhere.  However, he did agree to a payment plan.  Although I'm sure he has some btc stashed away and should at least refund you what he can.