How do I complain about a grade without being whiny?

I agree with China Guy in that if you feel you mastered the material and misinterpreted the question, asked for partial marks on having mastered the material.

It doesn’t sound like you have much to lose by bringing this through the appeals process - if he is a “few term” fill in prof that isn’t getting tenure and won’t be around much. But you may want to talk to one of your trusted profs about how it will be perceived. i.e. academic politics can be harsh, and you can be loved by your professors by proving a point with this one, or distrusted by them because you went over his head. And if you are looking towards grad school, having professors that love you will go much farther than one grade.

I’m sorry if I came across as though I’d magically found the actual question. I agree that his interpretation is (now) the more logical one, but I also don’t feel like the answer I gave deserves a 10% (which is what it got). I’ve talked to him, and he was unwilling to change the marks, saying that he’d boosted my grade above what I’d “actually got” already. I guess this time, I’m pooched.