https://www.bbc.co.uk/sport/formula1/59631665
Decent explanation of what went on, why and how.
The nub of it for me is that the race was decided by the decision to restart for the final lap, and they knew what that would entail. It exposes a peculiarity in the rules and that isn’t a great way to determine the outcome of a race, let alone a championship. I get there is a desire to finish races under green conditions, but when they agreed on that this is surely not what was intended.