Transactions can only either fail or succeed, nothing in between. They're atomic. The effects of the transactions aren't applied until the scripts have been val

Transactions can only either fail or succeed, nothing in between. They're atomic. The effects of the transactions aren't applied until the scripts have been validated in full. Uncaught exceptions and unhandled errors means the transaction validation failed, and it is invalid. If the transaction script on the other hand is set to deal with them and try something else instead, it might still succeed (there can be multiple alternate conditions that may independently grant right to transfer the coins).