> p(mud | rain) = 1.0
> p(rain | mud) = p(rain)
I'm not sure these statements say what you think they do. Assuming P(rain) > 0, the first statement p(mud | rain) = 1.0
is equivalent to p(mud & rain) = p(rain).
The second statement therefore implies p(rain | mud) = p(mud & rain).
Thus p(rain & mud) / p(mud) = p(mud & rain).
This, however, leads to the surprising conclusion p(mud) = 1.0.
According to your theory, it is always muddy.