Grandad's affair with Alice would be mentioned again in the third and final Rock & Chips (2010) episode "The Frog and the Pussycat (2011)", as the main reason why Violet threw her husband out of their house in Deptford.
During the scene where Del is pretending to be Triggers deceased grandfather, Rodney comes out of his bedroom wearing a Dan Dare T-shirt. 'ch0413930' was a science fiction hero that appeared in the Eagle comic book during the 1950's and 60's.
He has also appeared in other comic strips and a mini- series during the 80's and 90's.
During the last scene when Trigger is speaking to Del on the telephone, Del tries to have a private word with Rodney by holding the telephone against his chest. Unfortunately David Jason is holding the earpiece against his chest not the mouthpiece so Trigger would be able to hear everything Del says.
Del Boy walks out of what is clearly the bathroom, based on the mermaid wallpaper and sounds being made inside. On the door there is a sign which reads "4U2P" which can be said "for you to pee".