Since no alliance actually scored any points, nobody would be awarded points. But, say that a robot’s autonomous accidentally cancels out thier partner’s, then it’d be a bit more difficult.
And then you’d also have to factor in failed autons and, if both alliances fail and score no points, you couldn’t award any AP, despite both alliances moving.
It’s just an idea. And the rare backfiring auton might not even be a big deal, but I’ve seen it happen. (My partner accidentally flipped a cap to their color when grabbing a ball, and tipped auton in their favor.) As long as everything is not as it began, I would give the tie points out.
(But then there’d be the edge case of two robots shooting at the same flag in auton, leaving the field unchanged. But, because both alliances potentially would’ve scored points without the other alliance, I’d give them the tie points.)
(It quickly gets complicated, I guess. You’d have to accommodate edge cases in rules, and then refs would have to know all of these rules. I would justify it as “If each alliance would’ve won auton if the other hadn’t played, and the score is tied, then the tie points are given.” So the double-cap-flip-tie thing would just count as 0. )