If ffs had overwritten the beginning of the partition you would have ended
with a *different* error message and the kernel would not have crashed.
But more likely, the situation you describe could have never ever
occurred. Nobody else wants it this way, for a reason. You still haven't
thought about it enough nor you haven't learnt enough.
=> Your homework is to figure out what the other error message would be
and why.
(Trying to create a diff would help you to learn too, sending a bug report
will not.)
Regards,
David