Lerner's involvement was sort of a peripheral issue, IMO. The real problem is the vast numbers of Holder's People who are employed by the IRS, most of whom happily obstructed the processing of any "Tea Party" or similar group's documents, because those were seen as opponents of Barack.
They didn't need Lois telling them to do that, so it would've happened with or without her being aware of it. No practical way of dealing with that systemic problem, either, short of mass firings.
Everything about the Justice Department (from the FBI to its federal legal eagles) stinks to high heaven.