Here's the thing. There doesn't have to be an actual conflict of interest for Willis to be disqualified. If letting her represent the State would create an "appearance of impropriety" then the judge could boot her.
This could go either way.
I will say the money changing hands is a big deal. The judge singles that out today. There's no way to know who ended up on the better end of the transaction but that might not matter. The prosecution as good as admitted there was no way to show whether Willis actually paid back Wade for everything he bought for her. The judge could seem that enough.