This isn’t a bug, it’s a connection issue. It’s really common for everything else you’re connected on to continue working as normal, but have problems with one individual app or service. This is because not all services take the same path from your ISP and are not hosted in the same cities. More info and full explanation from Blizzard here: Common Technical Issues and Solutions - #23 by Drakuloth
As for leaver penalties, they are all treated the same, since they can’t monitor if someone pulls their internet plug to avoid loading a game or trying to dodge a loss. Lots more info here: Overwatch Technical Issues, SR Loss, and Leaver Penalties