Sadly, this decision is a bit more gray than you'd think. I'd suggest reading the decision yourself.
Cops show up for a domestic disturbance call. Bloody woman answers door with crying baby (obviously been beaten). They take douchebag away.
They come back later, she's still living there. They want to search for stuff, she says yes. Douchebag obviously refuses to allow it etc.
Now, there are some weirdness for this.
Who's name on the property ?
She's living there, does she not have any rights ?
etc ?
So, lets take this a bit different.
Happily married couple at home. Police knock and want to search. One says yes the other says no. What do you do next ?
As far as this particular case - my opinion after thinking about it last night and today is that judge should have thrown out anything discovered during the second search. Douchebag conviction wouldn't be worth chipping away at / poisoning the tree for the 4A. And they could have just of easily gotten a search warrant.
Why ?
Because although you have permission to search HER stuff, you don't have the right to search HIS stuff. Just because they're under the same roof doesn't change the law. There's also 'spirit of the law' stuff too.
As a possible argument against the above: if the lady had said 'there is bad stuff here', is that probable cause ?