“There’s little case law . . . ” because prosecutors are so rarely sanctioned or disciplined. This case is a rare bird, indeed! It will be interesting to see what befalls the jurist since as you well know, there’s an entirely different standard on ex-parte contacts involving judges. See, for instance, a case I posted in 2010 involving a probate judge’s ex-parte contacts and the difficulties of “piercing the steel wall of judicial immunity.” https://lawmrh.wordpress.com/2010/06/05/judicial-immunity-for-a-probate-judges-ex-parte-contacts/

But to elaborate further on how exceptionally infrequent this prosecutor disciplinary case is, also see, for example, https://www.propublica.org/article/who-polices-prosecutors-who-abuse-their-authority-usually-nobody
and
https://www.propublica.org/article/reversal-of-fortune-a-prosecutor-on-trial
and https://online.wsj.com/article/SB10001424052702304177104577307990622957100.html
and
https://lawmrh.wordpress.com/2011/03/31/no-proof-of-deliberate-indifference-as-prosecutorial-bacon-is-saved-by-high-court/
and
https://usatoday30.usatoday.com/news/washington/judicial/methodology-federal-prosecutor-misconduct.htm?loc=interstitialskip
and I could go on and on and on . . . .
– Mo