That's not their rationale. If they fail everyone then they get even more money when you have to re-register. Business 101: Create a monopoly and do whatever you want.
From what I've seen I think they change codes for the April exam and keep the same ones for the October exam. However, this is NCEES so they might decide to do the opposite of what you want just for fun.
A good reference is PCIs notes on ACI318-08 which is free and while it is dated most of the changes are organizational, not technical. The graphics help explain some of the more technical detailing requirements.
I personally don't think a single check would automatically trigger an unacceptable. If you stated that you didn't have time to check it I think that demonstrates your knowledge of the subject. Unfourtuanly it is up to the grader and his mood.
The people I took the test with simply recalculated it and the SE at our office suggested that might be what they wanted but agreed it was very poorly worded.
The vertical test did not seem difficult which scares me into thinking I fell for all their tricks. The lateral test seemed incredibly difficult. One of the afternoon problems I didn't even know what they were asking for. I Deffinanly anticipate having to take the lateral again.