Watch Rep. Jordan's stunned reaction to the latest IRS admission

IRS Commissioner John Koskinen surprised House Republicans late Monday night when he admitted he can't remember exactly when he first learned that Lois Lerner's emails were lost, or even who told him.

The closest Koskinen could get was to say he learned sometime in April that Lerner's emails were lost, about two months before the IRS told Congress. But he couldn't say if it was early, mid or late April, and said he has no idea how he learned that information.

That left a surprised Rep. Jim Jordan (R-Ohio) to press Koskinen for more information about what he said should have been a more memorable event.

"Did someone tell you in person? Did they send you an email? How did you get the information?" Jordan asked.

"I don't recall. I do not get emails on the subject so I'm sure… it was someone in person," Koskinen replied.

"This is been a major news story for the last 13 months, and you don't remember who came up to you and said, 'Hey boss, we lost Lois Lerner's emails.' You don't even remember anything about that situation?"

Jordan said it was such a big story, Koskinen might be expected to remember exactly where he was standing when he was told. But Koskinen indicated that part of his faulty memory may be caused by the fact that it was tax-time, a sign he may have been told in early to mid-April.

"Remember, I'm running an agency with 90,000 people and… we're in the middle of filing season," Koskinen said.