Mannix is talking to Gabe on the phone through the glass in the visiting area at the jail. Gabe has hung up the receiver on the phone on his side of the glass. In a camera shot from behind Mannix he is still holding his phone receiver but there is a receiver on the phone on his side as he is holding a receiver in his hand.
In Marysville, the Red & White cab's phone number on the front fender is KL5-8900, but the back of the roof light has only KL-8900. (KL5 = 555.)
Although this is supposed to be in a Southern state, all of the parked cars have California license plates.