I would still measure the undercut in that area, but it's kind of a waste of time since the underfill needs to be repaired no matter what. That's the practical side, now what was the "right" answer..........Just like the group you had looking at the samples, everyone had their own interpretation, such is the inspection world, "open to interpretation". We all play with the same rules, we just all look at them differently. I remember on my practical test, all of the samples were right on the verge of acceptance, and could have gone either way. I went with my best interpretation, and ended up scoring MUCH better than I had thought.
Just relax, and don't second guess every answer you put on the test, you did fine. I would bet you will be surprised when you get your actual scores and see how well you actually did (provided you spent the night time studying, and not in the lounge :)