A counter example

Not discounting the power of token issuance chaining as explained by Vittorio, I offer the following as an example of the fragility of the model.

1. Friend1 owes me money for hockey
2. Friend1 gives money to Friend2, says 'Pass to Paul'
3. Friend2 give money to WifeOfFriend2, says 'Pass to WifeOfPaul'
4. WifeOfFriend2 gives money to WifeOfPaul, says 'Pass to Paul'
5. WifeOfPaul gives money to Paul
   

This is of course the 'theoretical sequence', the actual broke down somewhere around the steps involving the more feminine endpoints.

Net net, Paul has no money, and hears alot of 'Oh what a nice summer dress, it it new?'