The Senate Finance Committee on Tuesday held a hearing on the Internal Revenue Service’s targeting of conservative groups, the second hearing of its kind on the explosive scandal that has rocked the Obama White House.

Witnesses at the four-hour hearing included former IRS Commissioner Douglas Shulman, who headed the agency during the period when it “aggressively” discriminated against conservative groups, Treasury Department Inspector General J. Russell George, and ousted IRS interim chief Steven Miller.

And despite the fact that the hearing was dominated by Shulman and Miller’s “I don’t knows” and “I’m not sures,” there were still a few noteworthy moments.

Here are the five most intriguing moments from Tuesday’s hearing on the IRS’s targeting of conservative groups [in no particular order]:

5. Ex-IRS Chief’s Pseudo “Apology”

Five Noteworthy Moments from Tuesday’s IRS Hearing

Ousted IRS Chief Steve Miller, left, and former IRS Commissioner Douglas Shulman are sworn in on Capitol Hill in Washington, Tuesday, May 21, 2013, prior to testifying before the Senate Finance Committee hearing on the Internal Revenue Service (IRS) practice of targeting applicants for tax-exempt status based on political leanings. (AP Photo/Charles Dharapak)

Sen. John Cornyn (R-Texas) asked former IRS Commissioner Douglas Shulman if he planned on apologizing for the IRS’ “overly aggressive” targeting of the senator’s constituents.

“I’m deeply, deeply saddened by this whole set of events,” Shulman said. “I’ve read the IG’s report and I very much regret that it happened and that it happened on my watch.”

“Is that an apology?” Cornyn asked.

“To your constituents?” Shulman responded. “I don’t know the details of our constituents. I don’t know what happened to them.”

Shulman continued, arguing that between 2008 and 2012, he had nothing to do with cases that involved political activity.

“So, it’s not your responsibility,” Cornyn said. “The buck doesn’t stop with you.”

“I certainly am not personally responsible for creating a list that had inappropriate criteria on it,” Shulman replied. “What I know, with the full facts that are out is – from the Inspector General’s report – which doesn’t say that I’m responsible for that.”

4. Sen. Hatch: You Lie!

Five Noteworthy Moments from Tuesday’s IRS Hearing

(AP Photo/Charles Dharapak)

Sen. Orrin Hatch (R-Utah) was one of the few senators to address the IRS’ political targeting as it happened during the 2012 presidential election.

So Hatch took the opportunity on Tuesday to give Miller a dressing down for not being, as the senator claims, forthright with Republican senators when they approached him last year with their concerns.

“Why did you mislead me and my colleagues?”

“Mr. Hatch, I did not lie,” Miller responded.

“That’s a lie by omission,” Sen. Hatch shot back. “There’s no question about that in my mind. It’s a lie by omission.”

“Frankly,” Miller added, “the concept of political motivation here — I did not agree with that in May. I do not agree with that now. We were not politically motivated in targeting conservative groups.”

3. Oh, Now  I Remember All About That Planted Question

Five Noteworthy Moments from Tuesday’s IRS Hearing

Steve Miller, center, flanked by former IRS Commissioner Douglas Shulman, right, and J. Russell George, Treasury Inspector General for Tax Administration, listens on Capitol Hill, in Washington, Tuesday, May 21, 2013. (AP Photo/Charles Dharapak)

Disgraced Internal Revenue Service interim chief Steven Miller on Tuesday took full responsibility for the planted question that put the IRS scandal directly in the spotlight, adding that the scheme was actually “an incredibly bad idea.”

“I will take responsibility for that,” Miller said in response to a question from Republican Senator Chuck Grassley. “The thought was to – now that we had the TIGTA [Treasury Inspector General for Tax Administration] report, you had all the facts. We had our response.”

“We thought we’d get out an apology,” he added. “The way we did it — we wanted to reach out to Hill staff about the same time … — did not work out. Obviously, the entire thing was an incredibly bad idea.”

Washington-based tax lawyer Celia Roady (i.e. the “plant”) asked senior IRS official Lois Lerner two weeks ago at the American Bar Association conference in the nation’s capital a prepared question involving the agency’s targeting of conservative groups.

Lerner’s canned response, and supposed “apology,” kicked off the major scandal.

Technically, Miller didn’t say last week during the House Ways and Means committee hearing that he didn’t know anything about the planted question. Still, his response today shows that he knew much more than he let on last week, which raises serious questions about his credibility.

2. Really, the Targeting Wasn’t ‘Politically Motivated’

Five Noteworthy Moments from Tuesday’s IRS Hearing

Senate Finance Committee Chairman Sen. Max Baucus, D-Mont. left, accompanied by the committee’s ranking Republican Sen. Orrin Hatch, R-Utah, questions ousted IRS Chief Steve Miller, former IRS Commissioner Douglas Shulman, and J. Russell George, Treasury Inspector General for Tax Administration, on Capitol Hill. (AP Photo/Charles Dharapak)

The message presented by ex-IRS officials in both hearings is clear: Although the targeting was bad, it wasn’t “politically motivated.”

However, Sen. Pat Toomey (R-Pa.) on Tuesday made a good point while trying to figure out who was responsible for compiling the list of conservative groups [from the Washington Examiner]:

If neither former IRS Commissioner Douglas Shulman, nor outgoing commissioner Steven T. Miller, can point to the employee or employees who hatched this plan, which they have repeatedly insisted they cannot, how can they be so sure that the individual or individuals behind it weren’t politically motivated to aid President Obama and the Democrats?

Obama and congressional Democrats are clearly outraged about what happened at the IRS; possibly not as much as conservatives would prefer, but it’s apparent that they are not pleased with what happened at the nation’s tax administration agency.

But until Treasury investigators or a congressional committee, or both, can figure out who was responsible for the targeting, and question them about how and why they developed their approach, it would appear premature, as Toomey suggests, to settle on a conclusion to one of the biggest unanswered questions that remain since the House Ways and Means panel launched the congressional committee phase of this scandal…

Why did it occur in the first place?

Indeed, if the targeting wasn’t “political,” then why did it happen at all? And if IRS officials aren’t exactly sure who is responsible, then how do they know that it wasn’t “political”?

1. Ex-IRS Chief: I Have no Idea How This Happened

Five Noteworthy Moments from Tuesday’s IRS Hearing

Associated Press.

The one thing former IRS Commissioner Douglas Shulman wanted to make clear during today’s hearing was he is totally ignorant of what went on under his watch.

“The man who led the Internal Revenue Service when it was giving extra scrutiny to tea party and other conservative groups seeking tax-exempt status told Congress on Tuesday that he knew little about what was happening while he was still commissioner,” the Associated Press notes.

“Douglas Shulman, who vacated his position last November when his five-year term expired, told the Senate Finance Committee he didn’t learn all the facts until he read last week’s report by a Treasury inspector general confirming the targeting strategy,” the report adds.

Shulman in his first public remarks since the scandal was broken said: “I agree this is an issue that when someone spotted it, they should have brought it up the chain. And they didn’t. I don’t know why.”

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Featured image AP photo. This post has been updated.