Well, it's not so much him looking away from the camera as his eyes looking to the right frequently. In the science of micro expressions, when someone unconsciously looks to their left, they are accessing memories and are usually considered to be recalling something and are therefore thought to be telling the truth. When a person looks to their right, they are considered to be accessing their creative/imaginative part of their brain and making things up, and are thought to be lying. People can try that for themselves when recalling a memory or trying to make up a story on the spot.
Millar keeps looking to his right whenever he's asked a question, whether it's an opinion or what he thought about something. You'd think, at least for when talking about Chronicle or parts which were actual memories, he'd look to his left to recall that information. He still looks to his right. And certainly when he's asked what he thinks about FFINO he definitely looks to his right.