Of course, but on our network a Windows user could, through
ignorance, configure her legitimately connect host to advertise
a route to a second interface on her machine.  

I guess your corporate networking policy is very different to anything I
have seen in over thirty years.  My wife works for a bank - there is
virtually nothing she can do to her laptop.

That's different 
from malicious intent requiring overt compromise of the
physical network.  The Rogue Router Advertisement problem
was so acute that an RFC was created. 

Indeed, so acute it was left to rot ever since.  If you have read the
RFC (I have now), it is clear there is nothing acute about that issue,
it virtually never happens.