I like to verify with a glance now and then, good thing i have plenty of room behind my mirror so i can see cameras ( most of them ) over the mirror, or i can bend forward a little to see the bottom of the cameras.
Bad thing is this time of the year, the little LED's are actually pretty hard to make out in daytime, so have to time my look for when i am in shade of something.
I must also admit that the flashing LED is what i would expect with a issue and a steady LED for operational, flashing i always tied mentally to emergencies.