Follow up: We had to push really hard, but the tester did finally agree to allow her to retake that one section and rescore the whole test. And she agreed to take out the exaggerated behavioral observations since they were "not clinically relevant."
So for others who may find themselves in the same situation, at least according to this psychologist, they looked into it and there is no rule that prevents retesting on the WIAT-II. (There *is* a rule that prohibits WISC and WPPSI retests within a year.) If you got a bad test result and you fight hard enough, you might be able to get a better shake for your kid, too.
