No ZFS never protects against data in transit. It makes 1 promise, that the bytes written to disk will be the same bytes read from disk at a later point in time

No ZFS never protects against data in transit. It makes 1 promise, that the bytes written to disk will be the same bytes read from disk at a later point in time. ZFS can't be responsible for being given bad data. Corrupt data looks just as writable as normal data to a storage controller. The article I linked shows how even bad ram isn't damaging to the integrity of a properly configured ZFS file system.