If a petrol company decided to skip a bus depot so they ran out then they are thick as mince. If buses don't run there will be more cars on the road, so more queues for petrol. Quite possible though.
There are limited drivers though, fewer than was needed to keep the supply going and its been teetering on the edge for months. It was broken long before any panicing. I'm pretty suspicious why no one has published how much fuel has actually been sold over the last few days, as maybe 2/3 of petrol stations are dry how much of these queues are just displaced users of other petrol stations.