Likely some recklessness going on there.

As a relevant hypothetical, though, let's consider the following scenario. Lets say, while he was stopped in traffic, a hijacker gained entry to his cab and started fighting with him for control over the truck. During the conflict, the truck driver accidentally caused the truck to lurch forward (let's say that, during the exigency of the moment, he confused the accelerator with the break), killing a pedestrian. Where does the criminal blame fall? The driver or the hijacker?

Let's add that the truck driver has 15 years experience, and even teaches defensive driving to new truck drivers.