Someone with fake ID by the name of "John" would have turned up at the Western Union office to claim the payment. For less than $5,000 they will pay out in banknotes. This 'someone' then meets a member of the scammers gang at a nearby location to hand over the money and gets a few $$ for his trouble. If he gets caught by the police for example the scammers couldnt care less. They pick guys up from the street and 'use' them once.

This is how most internet scams work. The scammer sending the message will be at a cyber cafe in a remote location (like Romania). Someone else will have prepared the original email content, or its been copied and pasted from elsewhere. As you can see from your emails, when you correspond further, this person shows a lack of english language and understanding of what you are asking for.

While I have been typing this, the address of the cyber cafe for this IP address has just come back to me as
71-75 Dr. Staicovici
Bucharest
ROMANIA