So the question is what do you choose to call now as North? Teams of four, a multiple teams qualifier [also called Round Robin in many places], straight imps.
The ruling is a simple judgement one: South hesitated noticeably [agreed] over 5♠ and North doubled. This went two off and East asked for a ruling.
Do you adjust the score?
As you will appreciate from a comment in another thread, I was one of the four players at the table and was surprised over the ruling. But I think it is more interesting to see what everyone thinks without telling you which player I was.