OMG, Steve, that's terrible.
The Daesin thing, I wonder... Could it be that blems are considered such for sometimes known-only-to-the-kami reasons, such as a hardening issue?
This one, which came a couple weeks after the first batch, may have been a discard. I am sure they don't tell Yangdu what's wrong; it's usually obvious what's wrong- a scratch, crack, etc.
Becuase of the work involved in making the MM, maybe a helper... well, I dunno. I remember when Bill put Bura "on report." But Kumar has made 1000's of khukuries and would know if it was over-hardened.
Please heal quickly and well.
Mike