Yeah. And for club championships, find some "truth serum," or at least give a little nudge to those who are particularly forgetful. But seriously, there's only one option: if you didn't personally clear the guard, you can only proceed if you're absolutely sure your opponent cleared it. Otherwise, it's at your own risk, and you'll end up with a clean tech loss.
And it's clear that the second or third guard was probably on the road, and your opponent cleared them. But it's not 100%, who knows what the generator will do.
That's why I suggest asking your opponent in ambiguous situations.
P.S. I'm fundamentally against tech losses in situations where they can be avoided. This situation falls into that category.