Let's not retread the whole question of how exit polls can only be useful outside of the U.S., even when some of the very same organizations are conducting the exit polls abroad...
What I'm saying is, I would bet purely Bernie supporters would be willing to pony up sufficient $27 donations to fund an independent exit poll that would, at the very least, give Bernie supporters peace of mind that the California primary recorded vote largely matches the actual vote, as indicated by a scrupulously conducted exit poll.