Could it simply be a ruse of Nick disappearing if he was owing money to drug-dealers etc and pretending to be dead to avoid them,makes it more convincing about his death by involving poor Dot?
But there is an even bigger mystery! Dot was talking to 'Nick' the other night and asked if he remembered her taking him to a harvest festival service and he was laughing at Ethel's little Willie - and Dot had made Nick a carrot suit - well little Willie died in 1992, so presumably was born some time after 1979/1980. Nick was born in 1959 so he would have been around 20 when Dot made him the carrot suit for the harvest festival!
Lankeela - I was thinking similar! When she spoke about little Willie I thought Nick would have been too old when He was around but couldn't quite work it out so thank you for that.