I assume they can still be disbarred for professional misconduct.
In general the justice system seems to have extensive functionality built to prevent its inner workings from facing the kind of personal liability that everyone else faces.
There are two extremes: (a) hiding evidence that helps defendants; (b) prosecutorial discretion to help their allies by not pressing charges. One may get disbarred for(a); however, no one gets disbarred for (b).
In general the justice system seems to have extensive functionality built to prevent its inner workings from facing the kind of personal liability that everyone else faces.