“He really didn’t think that he was a fatted lamb,” the actor tells THR about his character taking the blame. “He thought he was setting everybody else up and was surprised when he was hoisted on his own petard.”

[Warning: This story contains spoilers from the June 7 episode of Veep, "Testimony."]

Dirty little secrets always come out — especially when they contain information about a possible felony that could cripple a presidency right before a national election.

The data breach debacle, the dark cloud looming over the Selina Meyer (Julia Louis-Dreyfus) administration all season, finally came pouring down in the penultimate episode of the fourth season of the hit HBO comedy Veep. While under investigation by the House Judiciary Committee for the totally true alleged misdeed of illegally lobbying to torpedo her Families First Bill, the president and her inner circle had a day that quickly went from bad to worse.

While the administration categorically denied all instances of wrong-doing (and slowly dug themselves into bigger holes), former staffer and scapegoat Leigh (Jessie Ennis) turned the tables on the team, revealing that illegal lobbying wasn’t their most egregious crime — there was also that small, pesky problem that the illegally obtained information from the data breach had been unlawfully used to target recently bereaved parents.

Now on the hook for a felony and determined to save their own skins (and protect Selina’s presidency), each member had to point the finger at someone else. So who ended up taking the fall for the crime? None other than sarcastic schemer and communications specialist Bill Erickson (Diedrich Bader).

So how does Erickson move forward after getting thrown under the bus? “He really blames the people that are around him directly," Bader tells The Hollywood Reporter. "He’s going to try to get a pardon from the president of course."

THR caught up with TV veteran Bader to discuss the unique episode and how it feels to be the one thrown under the bus.

Since Bill really ingratiated himself with the team, how confident was he going into this trial? Did he ever have an inkling that he might be the fall guy?

Bill had felt like he had covered his bases the whole time. He’s a coward, so that’s what he does. Every time there was an order that was at all controversial he tried to put somebody else’s name on it. Bill [hadn’t] really thought he was going to get nailed for this.

How do you think he will react to this going forward? Will he be resentful or does he understand that all’s fair in love and politics?

As you’ll see in the next episode, Bill is an entirely selfish person. He doesn’t believe in taking one for the team because he looks out for Bill, like a lot of people. He’s very human in that way. Bill is actually extremely embittered by the process of being thrown on under the bus.

In hindsight, should he have seen this coming? He mentioned earlier in the season that he was the most vulnerable party in the administration because he was so new.

Last one in, first one out — you would think, but a lot of people are in denial about their strategies that they think are really going to work, otherwise they just don’t pursue them. He was genuinely surprised by it, [but] we all think our plans are going to work (Laughs). That was Bill’s biggest problem — the arrogance of power and the brightest men in the room; he’s one of those guys.

Since he was the one who orchestrated Dan’s (Reid Scott) ouster in the beginning of the season, is this perhaps karma for Bill?

It’s just the nature of politics. Somebody needs to be blamed and somebody is going down, and that’s just the way that it works. But yes, it is divine karma. From Bill’s perspective, he just thought it was nasty.

Beyond the season finale, how much do you know about your character’s future? Will you be back next season?

I don’t know. It’s really up to the new showrunner [David Mandel]. There has been no discussion of going forward, but I would love to because I really genuinely enjoy working on the show.

What was your reaction when you read the script and discovered your character was the one fingered for this crime?

They didn’t release the script, so I didn’t know [anything] beforehand. Then, when we were at the table read, Armando [Iannucci] was talking about somebody being thrown under the bus, and then it was me and I was like, "Woohoo! Okay we are going somewhere," because I didn’t know where we were going with [the data breach this season].

With the trial aspect of this episode, the whole show took on a unique tone and style that we haven’t seen before. How was filming this episode different from filming a normal episode?

They didn’t give us the script until that morning, so it was simply impossible to learn your lines — no one can learn them that fast. We didn’t rehearse. We were brought onto the set and everything was blindfolded basically — we couldn’t see any of the monitors, and when we walked in, that was the first time we saw the set or the other actors. I didn’t know who I was working with. It was all extremely unsettling which was precisely what Armando wanted: that initial response of really not being able to anticipate was going to happen. It was a thrill to feel so off your game. He robbed everyone of their opportunity to prepare themselves.

Did you end up shooting it in a more chronological order?

I can’t speak for the rest of the cast, but I wasn’t able to watch anybody’s testimony before mine and I didn’t know what was happening in the [rest of the] script. After my initial testimony, then I was able to watch for a while and then I went back in and did my final one where Bill realizes that he’s gonna be the guy.

So you shot the entire episode over a single day?

Yeah, the whole [52 pages] in a day. The scripts are much longer than something like The Goldbergs, which is like 34 pages. This was easier because our actual cameramen were mixed in with extras that they used as press, so there was this bank of cameras in front of you. For a while, I couldn’t pick [our cameramen] out of the crowd. [Eventually], out of my peripheral vision, I could see, oh, there’s camera A and there’s camera B, but it took awhile.

You joined the show as a guest star last season, but this year has seen you really join the core group of cast members. What was that transition like?

Well, Bill and myself were experiencing the same thing. We were [both] going into an already established relationship and trying to screw it up for everybody. I tried to mess up the actors as much as possible (Laughs). I’m kidding. It's a very welcoming cast. [What’s interesting was] when we rehearsed it [or were] sitting around and gabbing, everyone was so warm and welcoming, but once the cameras started rolling, they turned into the truly awful people they play on television.

The Veep season four finale airs Sunday at 10:30 p.m. on HBO.

Was Bill the right guy to take the fall? Should these people really be running the country? Sound off in the comments below and stay tuned to The Live Feed for more from Bader and the rest of the cast before Sunday's big season finale.

Twitter: @NotPhelan