It’s hard to imagine that someone would think a test on Torah would be bittul Torah.
No it’s not.
When I was younger, someone tried to convince me that the time I spent preparing for Krias HaTorah was really bittul Torah since I could have spent that time learning far more complicated inyanim.
He hung his argument on the fact that the Shulchan Aruch says that we are m’vatel talmud torah for megillah laining. “But how,” he asked, “could you say that? Megillah itself is Torah, no?” He then answered that since we could be learning G’mara or other more complicated matters, the megillah reading was actually bittul Torah (albeit required).
No, I didn’t buy the argument then, nor do I now.
The Wolf