Double Elim...

It is really not that hard of a concept that the final may be one or two games depending on the outcome of the first game.

Come again? The outcome of the first game, or the first first game?

The last and decisive game

Game, not games. When it references "finals" it means the disambiguation, not two finals/two games, etc. Again it's semantics and it's far from clear (for the majority), even if argued.