completely anecdotal but still: spoken to 2 petrol station workers this week and both have told me a similar story that petrol purchasing is done on a very controlled system based on purchase patterns of previous years (and many other seasonal factors) and that it is not very resilient to shock at all, you cant simply dial in more petrol for tomorrow, it takes weeks. So a lot of the problem, in their opinions, was a rush on the pumps and an inability to refill. Throw in a driver shortage and that is exacerbated.