What about the repeated failure to respond to his requests for medical attention (until the next-to-last stop, by which point he was already lethargic).
Every perp claims they need to go to the hospital. Easier to escape, and better food than jail.
Maybe they thought he was faking or malingering? Who knows how many other criminals riding in the van tried to claim they were sick or injured so they could go to the hospital instead of to jail?