There’s an excluded middle here: the defense can offer a range of possible occurrences. This is the lawyer speaking, and not the defendant himself speaking, of course.
They didn't say maybe a stranger took her, maybe her long lost father came back and killed her, they were asking them to believe THEIR story.
Evidence always narrows down the range of possibilities. In this case the evidence has narrowed it down to two: who threw the first punch.
We can NEVER forget that a trial is SUPPOSED TO BE UNFAIR to the state.
This is by design.
ALL the burden is on the state. ALL of it.
A prosecutor who tries to shift that burden via games with the jury will be toast.