The Internal Revenue Service belatedly revealed last Friday that it has "lost" an unspecified number of emails sought by congressional committees investigating the agency's admitted targeting of conservative organizations.

Then White House spokesman Josh Earnest lost his temper Monday.

But you would have to lose touch with reality to not be suspicious about how those emails went missing.

The spark that lit Mr. Earnest's ire during a press briefing aboard Air Force One:

A reporter expressed justified doubt about the IRS' contention that a "computer crash" destroyed emails, from January to April 2011, to and from Lois Lerner, who led the agency division that processed applications for tax-exempt status. A 2013 inspector general's report found that IRS officials, starting in 2010, subjected Tea Party and other conservative groups to selective scrutiny.

Utah Sen. Orrin Hatch, ranking Republican on the Senate Finance Committee, rightly called the unavailability of those emails "an outrageous impediment" to the panel's probe of IRS misconduct. Sen. Hatch also said: "Even more egregious is the fact we are learning about this a full year after our initial request to provide the committee with any and all documents relating to our investigation."

On Tuesday, other GOP lawmakers said the IRS also lost other officials' emails.

So a reporter fairly asked Mr. Earnest on Monday: "Do you think that's a reasonable explanation?"

Mr. Earnest tried to dismiss that question with this one of his own: "You've never heard of a computer crashing before?" The reporter replied: "I think emails generally are not stored on a computer; they're stored on a server somewhere. And the IRS' explanation for these emails going missing was that her computer crashed. So a lot of people are skeptical of, one, that that's a truthful answer, and two, that they're not trying to mislead Congress or trying to hide something in these emails. So I'm wondering if you think that's reasonable."

Finally answering, Mr. Earnest heatedly defended the IRS' computer-crash account as "entirely reasonable, because it's the truth and it's a fact, and speculation otherwise I think is indicative of the kinds of conspiracies that are propagated around this story."

Mr. Earnest said that "67,000 emails either sent by or received by Lois Lerner have been provided to Congress," adding: "There is ample evidence to indicate that a good-faith effort has been made by the IRS to cooperate with congressional oversight. And the far-fetched skepticism expressed by some Republican members of Congress I think is not at all surprising and not particularly believable."

Yet the notion of the IRS targeting groups based on their political persuasion would have sounded "far-fetched" before this outrageous practice came to light.

So would the notion of an IRS official repeatedly refusing to answer questions from a congressional committee, as Ms. Lerner first did in May 2013, citing her Fifth Amendment right against self-incrimination.

As for what is and isn't "particularly believable," the IRS, like the Obama administration in general, is running particularly low on credibility.

And that makes this scenario sadly believable:

A federal agency that would inflict its power on critics of the White House might also try to cover up those misdeeds with a "far-fetched" story about a computer crash.