What if a team is just beginning to develop their autonomous? If they had something that told the robot to go forwards x amount of feet to cross the first line, but somehow came out as x amount of inches, it might be seen as a "defensive autonomous" when it wasn't. If a robot hit them the first time they tested this and they didn't know it did this, should they be given a yellow card?
If they were, that would really discourage teams from attempting to write and autonomous mode in the middle of a regional. Writing code halfway through Friday is a time honored tradition, and I'd hate to see it go away.
The point being, until you see the team do this multiple times in a row, don't assume anything.