He Ain't Heavy, He's My Uncle - S7-E6
Visible crew/equipment: When Del is looking out the window at the end, you can see a camera reflected in the glass.
Miami Twice: The American Dream - S7-E8
Visible crew/equipment: When Del asks Rodney if he is still going to Miami after Cassandra says no, Rodney replies, "Possibly." As he walks off, you can see a studio light blurs the camera at the top of the screen in the middle.
Visible crew/equipment: When Cassandra is on the phone to Del at the start, a boom mic shadow is visible.
Visible crew/equipment: After Albert has filled up the baby bottle with the proper water, Myles, Rodney, Del and Albert are all back in front of the shed. In one of the shed windows, a boom mic can be seen moving around.
Miami Twice: Oh to Be in England - S7-E9
Visible crew/equipment: At one point when Del is searching for Rodney around the mansion, you can see the shadow of a camera on the wall.
Chosen answer: An apparent long string of illnesses.