Stopping someone running away how? Follow the train of thought. What were his good intentions when he caught up with them? Was he going to stop them getting away by -
By asking politely? Now that would be well intentioned.
Or by ramming them off the road? That's not well intentioned.
People don't think that rationally. He acted on instinct. Once he caught up with them it would be a whole new ball game. He would have been attacked if he tried to detain them.
For the umpteenth time it wasn't proved he DID ram them off the road intentionally. If it was as @gordondaviesmoustache said the charge would have been more serious.