PLEASE TELL ME

I rewatched the anime (been doing it multiple times) and only got to read this now. I have heard that if you crash into someone, it is better to ensure that they died. Why? Coz if they are alive, not only you will end up in jail, but you will also pay for medical bills (which could be really expensive depending on the injury). But if they died, it is a one-time expense. Again, that is what I have heard.