Yes. It sounds like your ``really-high end installer'' is unable to read directions.

In all likelihood, the constant power of the car is attached to the switched power of the empeg, and possibly vice versa.

There's info about this sort of thing in the FAQ (and the manual, for that matter), but, in general, the empeg will totally turn off after a few minutes (configurable). While the LED is blinking, it's in a standby mode.