Due to the extent of the race and the different car performances, cars can have a +1 lap difference. So if a SC is deployed, you can have a situation where you have P1-P19-P20-P2-P3-P4-etc (P == position) (example similar to the actual positioning).
The FIA ordered drivers to pass +1lap drivers, so the physical order of the cars reflected the actual position order. This was controversial. Max (P2 at the time) overpassed five +1lap car. Furthermore, he changed tires for "faster ones". When the race restarted (with just 1 lap to go), he passed Hamilton (P1 at the time) and won the World Drivers Championship.