I don't scrapbook, but I love to look at the pages filled with pictures that my friends/family make. 25 isn't out of the ordinary and you could mention that to your DS's teacher - an example would help. Just phrase it as "Just so you understand why he didn't give the expected answer..." Make a joke out of it and see what happens, but don't grade-grub, lol.
My kid got this question wrong in Kindergarden:
Q: How do students get to school?
1. Walk 2. Bus 3. Car 4. Boat 5. Plane
She circled all of them and was marked wrong - only the first three were considered the correct answer. She argued with the teacher about it. In DD's opinion:
4. Boat was correct because her teenage babysitter took a ferry to get to high school every day.
5. Plane was correct because college kids take a plane to get to their colleges. We had just given a friend's son a ride to the airport the day before.
I agreed with DD when she told me about it - they were all valid answers. The teacher wasn't impressed, saying DD was "overthinking." I mentioned it at the conference.
It's an interesting point from a bigger perspective: these questions are good examples of the problems of developing standardized tests. The Testmaker's "expected" correct answers aren't the same as what the student has experienced.