When Helen and Will see, on Helen's smartphone, the video of a Pterosaur flying past Big Ben, Will says, "London calling". In the 1930s the BBC World Services radio programs started with "This is London calling". During WW2 this identifying line was used for programs broadcast into occupied Europe. The phrase 'London Calling' has had heavy usage in England ever since.
After the briefing with heads of the world's sanctuaries at the beginning of the episode, the video feeds from particular cities start to disappear. Before switching out, one of the sanctuary heads says "do widzenia," which is a formal Polish expression meaning "goodbye".
Henry says that at the time of the Mombai EMP Kali emitted a magnetic burst that shifted magnetic north by .00001 degrees. If he ment degrees latitude, that would be a shift of about 44 inches. Given that the magnetic north pole constantly moves in loops of about 50 miles each day, how could he tell?
Both Amanda Tapping (Hellen Magnus) and Paul McGillion (Terrence Wexford) appearead in Stargate Atlantis
The pterosaur may be a reference to Torchwood, a Doctor Who spinoff show based in England.