Answer :
It’s not *supposed* to happen, but of course you can find instances where it does.
Some judges like to hand out longer sentences. Some are just corrupt.
It’s also possible that having the victim survive can work against you as they can now testify against you. An emotional plea from a victim can get a judge pretty worked up.
I don’t remember where I heard it, but a lawyer once advised a client that, “If you run someone over, be sure to back over them again and finish the job. Their family will get less money for a corpse than for a disability.”