> I can't see a normal person willingly accepting this sort of risk

A lot of Germans did in fact do it. So... there. Even my father considered doing it, being ever suspicious of the handheld tracking device that is the smartphone we forced on him.

There's not much police will (or can) do once it's established that you traded SIM-cards. It's actually discussed in the first article I linked.

There's also a good chance you weren't even remotely physically close to the phone/sim when the crime was committed.