I interpreted that as George trying to control his anger. I'm sure it must have been very upsetting to be accused of molesting your child in such a public forum, and George is known to be volatile. I saw him as taking a second to control that anger and then I felt his response was very believable.
Tink
I think it's because until that moment, he himself did not know if he was gonna jump under the bus and lie for ICA or not. when he raised his head, that is when he knew he would not lie to save her.