This is a weird instance to use this law. I've only ever heard examples where the odds of killing are high, such as armed robbery. So, a getaway driver when they take the armed robber to/from the scene. If the guy ends up shooting and killing someone the driver gets charged.
I don't see how anyone could reasonably think that stealing from cars would end up with someone else being hurt or killed. They didn't even take any weapons.
Two guys breaking into cars got caught, one went quietly while the other ran, drove off, and (much later) hit some cyclists killing them. Both charged with murder.