[FotoPlasma]

Yes, the rules are the rules.

Three teams, two matches. One team plays in both, the other two are mutually exclusive.

As for the whole "broken robot" situation, I would assume that you don't have to put the disabled robot on the field, but the third team, who has presumably already played a match, cannot replace them ("no exceptions"). A human player would be fielded for the alliance, but there would be no robot.

If it is the case that this rule was broken, let's hope that it's reinforced for the upcoming regionals.