Agent Zeigler wasn't in that meeting so he can't testify to it.
Shapley was, but his statement is different than what you claimed. He said that Garland requested "special counsel authority" at the same time as the referral to DC.
- IRS Supervisory Special Agent Shapley memorialized in an email a meeting where U.S. Attorney David Weiss told multiple people that he was not the deciding person on whether charges are filed. Weiss stated that he went to the D.C. U.S. Attorney to request charges there but was denied. Weiss also requested special counsel authority when it was sent to D.C. and the Justice Department denied his request. No witnesses at the meeting have refuted Shapley’s summary of the meeting. In fact, his supervisor said he “covered it all.”
Weiss says he didn't request special counsel authority but was in talks about possibly doing so with the agency. There's nothing there saying he requested special counsel authority AFTER he was turned down by California and DC.
United States House Committee on Oversight and Government Reform
oversight.house.gov