Or he forgot to pay his ebay subs on time.
Happened to me once due to changing credit cards. All your listings are pulled and same message is sent to bidders on your items.
This is probably the most likely as if he was scamming he would not have sent the goods out.
In any case as you received the goods seems honest enough.
Send an email asking what's up as you might want to trade again.
Cheers,
Gary.