Thanks for the help you, you took the words out of my mouth haha......Per the question about a previous entry, a prior entry could always be cancelled out with a new entry.
Remember business is still take place on the front end and the blockchain is a back end ledger to verify the data...In the real world, if you accidentally sent an incorrect contract and that metadata hit the ledger, the user would simply cancel the 1st contract and send a new one, this would append the ledger and one could see that a previous version was cancelled and a new contract sent. There are also ways to to verify version history as was mentioned in that previous comment.