To sum up this passage:
First, Delta 1989 misses the transfer to the next sector because of the turmoil caused by UA 93. At this time (about 9:40) this must be the hand-off from Lorain sector to Bluffton sector, the super-high sector of Cleveland Center which is adjacent to (west of) Lorain sector. As a result, Delta 1989 is not in radio contact with Bluffton sector for several minutes.
Then, the Delta 1989 pilots get a message from Delta Airlines to land in Cleveland immediately.
Then, the captain of Delta 1989 requests an immediate diversion to Cleveland, being back on the frequency.
At last, Cleveland Center, surprised by the request and unaware that Delta Airlines has ordered the captain to do so, gets suspicious of the flight.
This "Lynn Spencer version" of the diversion of Delta 1989 is completely wrong in terms of chronology and facts and easily disproven by the best imaginable source: the radio transmissions between Cleveland Center and Delta 1989.
9:38:52 (Lorain Radar) roger delta nineteen eighty nine there's traffic for you at eleven o'clock and fifteen miles southbound fourty one climbing looks like he's turning east fly heading three six zero
9:39:00 (Lorain Radar) okay thanks delta nineteen eighty nine
9:40:57 (Lorain Radar) delta nineteen eighty nine fly heading two eight five
9:41:00 (Delta 1989) two eight five delta nineteen eighty nine
9:43:56 (Delta 1989) cleveland center delta nineteen eighty nine
9:44:09 (Delta 1989) cleveland delta eighty nine
9:44:10 (Lorain Radar) delta nineteen eighty nine
9:44:12 (Delta 1989) company wants us on the ground in cleveland
9:44:12 (Lorain Radar) say again
9:44:16 (Delta 1989) the company wants us to divert to land at cleveland
9:44:19 (Lorain Radar) delta nineteen eighty niner roger fly your present heading descend and maintain flight level three three zero expect further vectoring for cleveland
9:44:24 (Delta 1989) delta nineteen eighty nine three three zero present heading
9:44:27 (Lorain Radar) delta nineteen eighty nine roger and contact cleveland one one niner point three two
9:44:31 (Delta 1989) nineteen thirty two
With this transcript at hand, it is easy to show up Ms. Spencer's grave errors:
1 - Delta 1989 does not miss the hand-off to the new frequency. It affirms the Lorain controller's request to change the frequency to 110.32, which is Bluffton sector.
2 - The message of Delta Airlines to land in Cleveland arrives before Delta 1989 shifts to the new sector, not afterwards.
3 - The controllers of Cleveland Center are well aware that it was Delta Airlines who ordered the pilots to land in Cleveland - simply because the pilot told them.
Unfortunately, the source for the misinformation in Spencer's book is not clear. It is absolutely clear, however, that Delta Airlines' diversion order was well known among controllers and not the reason they surmised it to be a hijacking. Therefore, we can also throw another account onto the dustbin of history:
The Delta flight wants to land in Cleveland? And the captain's request comes before he can know that the FAA wants every flight down. On this day, the fact that the pilot requests to be rerouted before he is ordered to land seems suspicious. Why the urgency?
Controllers don't know that Delta officials, also concerned about the flight, have ordered Werner to land in Cleveland. They continue to send messages to Werner. In code, they ask him if all is OK. Yes, he responds time and again. He doesn't know why they're so worried.
Like Lynn Spencer, USA Today is flatly wrong. Controllers were well aware that Delta officials had ordered the pilot to land in Cleveland.
So the question is still pending: Why indeed was Delta 1989 considered a hijack? Why is there so much misinformation going around on this matter?