If it wasn't for Mitrovic, Serbia couldn't even be in a position to qualify. It happens.
If I had to choose a country to qualify over Serbia, I'd choose Scotland in a heartbeat.
I still remember the qualifier in 2013, I think, when Tartan Army came to Serbia to support their team. Just before the match, a ton of snow fell and officials were thinking of postponing the match. Those lovely Scottish bastards entered the pitch during the day in their kilts, grabbed shovels and cleaned up every bit of snow, so the game wasn't called off.
Serbia won 2-0, the Scots sang their lungs off, drank a month's production of beer, donated some money into charity and fucked off.
Class story.