When Rex started recording in the previous episode, his battery has 54 minutes of power left. When he records around the camp in this episode, he still has 54 minutes of battery (which drops to five minutes later on) - good going without a charger.
When Colin Maloney is talking to Ralph Coltrane about moving Vera's car to The Constitution Mall in San Pedro, he refers to it as a "large car park"; car park is a British term. In the U.S., it would be called a "large parking lot."