Oh, I see what your are saying ... that zfs can detect corrupted files, true.
Whats likely to happen in this case is this:
The first blocks of the disk contain the superblock, labels-descriptors and other filesystem metadata. Most of which will be sitting in cache. The damaged overwritten area at 0mb won't be noticed for some time - like next time the volume is mounted. The filesystem will eventually notice the damage and go into some recovery mode or halt to protect itself. Zfs has lots of redundancy so the beginning volume labels could be rebuilt.
One benefit of zfs will be that you can tell which recovered files are good or bad.
Whats likely to happen in this case is this: The first blocks of the disk contain the superblock, labels-descriptors and other filesystem metadata. Most of which will be sitting in cache. The damaged overwritten area at 0mb won't be noticed for some time - like next time the volume is mounted. The filesystem will eventually notice the damage and go into some recovery mode or halt to protect itself. Zfs has lots of redundancy so the beginning volume labels could be rebuilt.
One benefit of zfs will be that you can tell which recovered files are good or bad.