"Surviving Christmas" is the only episode after her introduction not to feature Julie. At first it seems strange, until you remember that Julie was heavily pregnant at this point in the series and was in no condition to do a training course on freezing mountain terrain.
In "Gavin Featherly R.I.P." Brittas is remarkedly apathetic to the fact that the family dog is dead. It seems quite cruel until you remember that when Helen got the dog back in "The Chop", it led to him almost losing his job.
The fact that so many random characters die in such chaotic ways actually makes sense when you a) remember how safety conscious Brittas is and b) have seen the ending which reveals The whole show is All Just a Dream - Brittas is basically imagining the the absolute worst-case scenario in which someone dies via poor safety procedures - the fact that Brittas himself doesn't catch on during the show also makes sense, because this is a dream, and dreams are usually pretty much predetermined, causing you to make poor decisions you wouldn't normally make. The real Brittas is creating these scenarios subconciously!
Considering that: 1. Tim never knew his father, 2. Tim's family comes from Eastern Germany and 3. Tim's real last name is Göebbels, it is likely that Tim descended from Joseph Göebbels, chief propagandist for the Nazi Party.
Before Series 4, Brittas and Helen are established as having 3 children from Helen’s previous marriages (five after the birth of their twins). After Series 4, they only have 4 children, the twins and Helen’s two stepchildren. Now note how Helen can not only not keep track of how many children she has at the one time, but constantly misplaces them. Could the reduction in children be because she misplaced one and was never able to find them?
