When the Internal Revenue Service (IRS) said that Lois Lerner, a former tax official at the center of a congressional investigation over targeting of conservative groups, could not produce an untold number of emails during a time-frame crucial to the investigation due to a hard drive failure, it seemed convenient, but entirely plausible. When it was later revealed that six more IRS employees could not produce certain records related to the investigation, at least one due to another computer failure, it seemed more than a little convenient. But still, these things happen.

Now, it appears that there are even more records that the IRS may not be able to produce due to employee computer failures. In transcribed testimony today, IRS Deputy Associate Chief Counsel Thomas Kane, the individual in charge of producing documents for congressional investigators, said that a number of additional tax agency officials "have had computer problems over the course of the period covered by the investigations and the chairman's subpoena," according to a House Oversight Committee release this afternoon. Kane placed the total number as "less than 20." The group apparently includes Justin Lowe, an exempt organization technical advisor, David Fish, who was the manager of Exempt Organization Guidance and an "advisor to Lois Lerner" (who ran the tax exempt division), according to the Committee release.

Details of what sorts of records can't be provided are still unclear, as are the particulars of the computer problems involved. But on the surface, this is pretty incredible. Yes, hard drives crash and computers malfunction, but increasingly, this strains credibility. Based on what we know, at least, this looks pretty bad for the agency, even if there was nothing particularly damning in the lost records and emails. The IRS appears, at minimum, to have a widespread problem keeping and storing records that might be of interest to congressional investigators.

Or at the very least, senior officials do not have any idea how the data retention process works. The other interesting detail revealed in the Committee release is that some email backup tapes may still exist. When Kane was asked about a June IRS memo to Sens. Ron Wyden (D-OR) and Orrin Hatch (R-UT) stating that "back-up tapes from 2011 no longer exist because they have been recycled," he responded hesitantly. There was "an issue" with whether the backup recovery tapes were actually destroyed, he said. "I don't know whether they are or they aren't, but it's an issue that's being looked at."

That seems like the sort of thing that the IRS should have been confident, certain, and accurate about the first time around, and the conflicting stories—first agency officials are certain the records were destroyed, later they are not so sure—does further damage to their credibility. The most generous possible story here is that the IRS is massively sloppy and incompetent in its records retention processes, and as a result suffered some extremely convenient data losses.