The driver isn't owed a dime. The minute he left the shipper without the implicit approval of dispatch he literally and figuratively abandoned the load contract. Whether one just so happened to have gone dry run after he left is irrelevant, since at the time he left, the load was not a dry run.
The shipper can tell the driver it's a dry run, ... but you don't leave until .... dispatch tells you to leave ....
If you leave prior to getting loaded or before the customer determines it's a dry run, you have breached the contract. It's that simple.
I agree. It is that simple and that cut and dry.