The latest development in the IRS scandal seems incredible — and incompetent.

Lois Lerner, the central figure in a congressional probe of IRS officials harassing tea party organizations, refused to testify before a House committee. Now the IRS says Lerner's e-mails are missing from the entire two years that Lerner's office is alleged to have singled out the organizations' tax-exempt applications for extra scrutiny.

IRS officials told Congressional investigators it could not recover e-mails from the crucial period of 2009 to 2011 after Lerner's computer hard drive reportedly crashed sometime in 2011.

That time period is critical, since the practice is alleged to have begun in the spring of 2010.

Congressional Republicans are justifiably skeptical. They're trying to figure out whether Lerner was acting on orders from Washington. The e-mail vanishing act only increases suspicions that she was.

U.S. Rep. Darrell Issa, R-Calif., chairman of the House Oversight and Government Reform Committee, had subpoenaed the damaged hard drive, along with any external hard drives, thumb drives, other computers and “all electronic communication devices” issued to Lerner. The IRS responded saying it had enlisted IT professionals to restore Lerner's hard drive, but they were unsuccessful — and then they disposed of Lerner's broken hard drive, following what they called standard protocol.

But there are other standard protocols at the IRS. One is to back up all e-mails that are considered an “official record.” Not only that, but there needs to be a hard copy filed, too. By “official record,” the IRS policy refers to any correspondence “created or received in the transaction of agency business,” “appropriate for preservation as evidence of the government's function or activities,” or “valuable because of the information they contain.”

It's not clear if Lerner made any hard copies of any e-mails. None have been turned over to congressional investigators.

Many information technology experts are skeptical of the IRS claim that the e-mails could not be recovered. One IT expert, a former Microsoft program manager and Army intelligence officer, said it's possible the IRS is telling the truth about Lerner's e-mails — if the federal agency is “totally mismanaged and has the worst IT department ever.”

What seems most offensive about Lerner's lost e-mails is that the IRS branch under her direction probably would not have had the patience to accept the very explanation it offered the congressional investigators. The IRS has a reputation for intolerance, and it likely would not have tolerated such incompetence from the Tea Party organization it's alleged to have singled out for extra scrutiny.