They are attempting to adapt their fuel pump to use Lightning and require a refund address due to pre-payment requirements with change being returned at the end of the sale. The writer also questions whether real-time micropayments would be feasible for automobiles, considering issues such as latency and bandwidth requirements. They ask if there could be automatic failover routes in case one of the hops goes down during delivery, but acknowledge that this may be challenging with onion routing. Despite these concerns, the writer believes that there are many other use cases where a refund may be desired, hence the inclusion of a refund address option in BIP 70.