I think we've seen one of old classics attempted here.
Talk a load of shite about something (in this case compass needles being moved by a vortex) then get pinned down to the point where there's no answer, so just come out with something ridiculous to distract.
Today it is "there's only one direction, north. No such thing as east, south or west".
Similar to how not all right angles are the same. A bombastic statement that diverts focus (pin point level focus) elsewhere.
Like every so often there'll be a bit of "debate" he gets stuck so just throws in "no proof whatsoever"