Broadly there were two ways the rule could be applied while under the safety car.
If they don't let any cars through, Hamilton wins the race in pretty much every scenario.
If they let all the cars through, the race finishes under the safety car and Hamilton still wins.
The obvious problem is that neither side can be 100% sure of the outcome in the first scenario, but considering the winning margin was just over 2 seconds, and it appeared that Hamilton backed off towards the end of the final lap, I'd say it leans in his favour quite considerably.
Edit: what
@Leg-End said