Throughout the series Rockford is out of prison because he was pardoned but in this one Hayes is his parole officer who sent Rockford back up for breaking parole.
Rockford is pouring a glass of milk when Marcus Hayes starts knocking at his door. Then Rockford closes the door after he tells Marcus to get lost. Marcus starts knocking on the door again and the lid to the milk is on the counter. When Marcus jumps inside the trailer, Rockford goes to the milk again, but this time the lid is on the milk jug.
When Marcus is knocking on Jim's trailer door Jim reaches into the cookie jar and the back lip is broken: a large piece along the top edge is missing.
When Marc and Jim get on the elevator at the end, one can see light between the now shut elevator doors. If this were a real elevator, it would have door brakes on each door. A door brake is a panel that would press in if it closed on something or someone. If these panel were to press in, the doors would stop closing and open again. This is what keeps elevators for injuring someone. But these doors did not have door brakes, otherwise, when the doors closed, no light could be seen between the doors, revealing the fact that these elevator doors were just set props.