Can a hearse carrying a corpse be in the carpool lane (legally)?
I concluded that if we are going with the purpose of the carpool lane, to reward those who carpool, then no it would not because a corpse cannot drive a car and therefore you are not saving the environment by sharing your vehicle with it.
The carpool lane has always mystified me because it is one of those very few things that runs very much on the honors system. In my opinion, driving by yourself in the carpool lane is like cannibalism: it's just morally wrong and something you don't do. And yet there are those that do.
There are also poachers though, so I guess I shouldn't be too surprised.