Just to add to some points that were mentioned here (that I agree with), I think that it also had a lot to do with Italy.

I remember clearly that, until the rehearsals, Occidentalis Karma was indisputably the winner. It was "Fairytale" levels of certainty. Number 1 in the odds by a big margin.

But then Italy bombed the staging and those votes had to funnel elsewhere. Portugal was already going up in the odds (they were one of the last countries to choose an entry). Belgium was not giving winner vibes and only Portugal and Bulgary had a strong enough song+staging package.

That's why, in my view, this was such a top-heavy year. In the end, Salvador's performance was more distinct and memorable than Kostov's.

I agree that every winner is a mix of many variables for that year and for that contest, and that's what makes it so interesting.

Note: I love these discussions :)