The President, sitting with his legs crossed and his hands folded in his lap, was intensely aware of the television cameras that were recording his every expression. "I have nobody to talk to," he thought to himself as he tried to absorb it all in an instant. "My God, I’m Commander-in-Chief and the country has just come under attack!"
There was no way he could conceal his feelings of shock and dismay at the horrible news. There was a fleeting look of panic in the President’s eyes as Card stepped back. "It was a surreal moment," Card later said. "It was immediately obvious that it was neither an accident nor a coincidence."
But without all the facts at hand, George Bush had no intention of upsetting the schoolchildren who had come to read for him. The rest of the children’s story about the goat did not register with him at all, but the President, raising his eyebrows and nodding, interrupted the second graders to praise them. "Really good readers, whew!" Bush told the class. "This must be sixth grade.", Reference
There’s also an interesting and informative eleven page account of the entire timeline, "Revealed: what really went on during Bush’s ‘missing hours’ " in The U.K. Daily Telegraph.