Foreknowledge of two more hijacked planes around 09:03 heading towards D.C.

This article discusses the statements of two important persons with regard of foreknowledge about the unfolding crisis.

In following CNN-interview Secret Service agent Nelson Garabito says, that shortly after the second plane-crash he was informed by the FAA, that there were two "outstanding planes" heading towards Washington DC. One was "approximately 30 minutes out", the other "was 45 minutes" out.

In the 911-commission reports stands ...

"Shortly after the second attack in New York, a senior Secret Service agent charged with coordinating the President’s movements established an open line with his counterpart at the FAA,who soon told him that there were more planes unaccounted for—possibly hijacked— in addition to the two that had already crashed."

This account is based on the statement of Garabito. He says his FAA-counterpart, Terry van Steenbergen, said (a few minutes after the second plane crash) to him, that ...

"... there were 4 planes believed to be hijacked and 2 outstanding believed to be travelling to D.C"

Mister van Steenbergen describes the moments ...

"On 9/11
He went down and saw the second plane hit. All his information was coming from Nelson Garabito of the secret service, who was calling him from the White House JOC. Nelson fed information to him. This was Steenbergen only outside source. He doesn´t know how Nelson got his information. This was received within 30 seconds of the 2nd plane hitting the World Trade Center. Garabito said: "What should we do?", Steenbergen said: "We need to turn all the planes away from Washington. He concurred. The three people in his office called Dulles, National, BWI to tell the pilots to turn their aircraft out of class B airspace. (...) Once we started the planes moving outbound (...) all inbound planes were considered hostile. Steenbergen said, we needed fighters airborne. We had three people here in his office call over to Andrews, Langley etc. to see, if they would launch some fighters. Diane Creen, Karen Pontius, Scott Hagen were in his office that day. (...)"

Important questions:

-How could Terry van Steenbergen knew shortly after 09:03 of two outstanding hijacked planes flying toward Washington and the FAA not? Minutes after 09:03 neither Flight 77 nor Flight 93 were assessed as hijacked flying towards Washington D.C. Why, if Terry van Steenbergen knew about the additional hijackings before the phone call of Garabito, why did he not act immediately, why did Steenbergen wait until Garabino phoned him?

On the other hand, the statements of van Steenbergen could also be interpreted differently - in that way:
Steenbergen was informed by Garabino in the call about the two outstanding hijackings and not about the presidential movements on 911. Although the Steenbergen-interview is also about their handling of presidential movements before 9/11, in the section "On 9/11" Steenbergen is focused in information regarding hijacked planes, and he says explicitly, that "all his information was coming from Nelson Garabito" and, that "he does not know how Nelson got his information." The question is, how the secret service could have foreknowledge about the unfolding crisis, and why the secret service warned the FAA at all?