NSEC3 hash collision

[Klaus Darilion]

Hi!

I just stumbled across section 7.1 of RFC 5155 
(http://tools.ietf.org/search/rfc5155#section-7.1):

As the "owner name" is hashed, there is potential for a hash collision. 
What confuses me is:

>    If a hash collision is detected, then a new salt has to be chosen,
>    and the signing process restarted.

But the salt is not chosen by Bind, but provided manually. So, I wonder 
how Bind reacts if a collision is detected. Or is Bind not checking for 
collisions at all?

Thanks
Klaus