And I disagree. Ask Lerner a few questions, maybe half a dozen or so. Let her claim the 5th each time, THEN declare the witness uncooperative or recalcitrant, excuse her with notice of probable recall.
Video of a government employee claiming 5th amendment protection when being asked questions about what happened under her watch at the IRS would have far more dramatic impact than merely telling her "ok, maybe see ya later, have a nice day".
In normal times, you'd be absolutely right.
But these are highly abnormal times. The public is poorly informed, and confused by years of news media abuse and public mis-education. Many of them despise Republicans, even those who agree with them on a considerable number of issues.
Further, the mainstream media could not be counted on to broadcast Lerner's serial 5th Amendment-taking; instead, they'd manage to make it appear as though the Big Bad Republican was beating up on a woman.
I still think she will be recalled, but this time with a legal determination that compels her testimony. Others will come forward, too. At this moment, with scandals swirling all over this Administration, a bit of patience is a virtue.