It's not about getting excited. It's about how the cut was not made.
Saws do not produce variable thickness like this.
Completely rules out any sawing technique. Not that they were able to do it by sawing anyway,
They had no material that could do this to granite, nor has any been found.
Perhaps that doesn't rule out Aliens, but if it was, maybe it's why they didn't hang around, or maybe they were defeated by someone else, who did things rather better.