While it seems to be same as throwing money into fire, it is more of a lack of atomic transaction problem. The backed up wallet has the state snapshotting the account balance. If the new transaction is invalid, it can always be rolled back to the old snapshot. That's how transactional database works. It looks like the new transaction is not atomic. Part of it has been committed (published) and part of it not saved. The system crashes and the account is in the inconsistent state, thus losing everything.