This looks like an unfortunate case of target fixation. You tend to move toward where you look and he was looking at the giant truck heading toward him.

Edit: Target fixation can also help you predict how other drivers are going to move. A driver who wants to change lanes will often veer slightly toward that lane as they check their mirror and blind spot. A second later you will see them turn on their blinker (or not if drivers around you suck) and then shift lanes.