What some people call gaming the test, or test prep (for achievement-type tests like the SAT/ACT), others call learning the material. Other than the SAT writing, which really can be gamed by babbling, most of the others discriminate against poor test takers, but can't really generate significantly inflated scores unless you actually cheat.
In general, test prep for ACHIEVEMENT tests is broadly considered ethical as "learning the material" and we see many schools "teaching to the test".
Meanwhile, test prep for IQ tests is broadly considered unethical as gaming the system or cheating, yet is also widespread. This may explain why many schools do not accept outside test results but rather utilize tests which they may believe have not been "leaked", results which not been frankenstiened or superscored, and subtests which have not been selected after-the-fact for having the highest scores. This may also explain why some schools administer multiple tests and look for consistency among the results.
In the case at hand for the thread topic, links in previous posts indicate that the parent mis-represented another student's ACHIEVEMENT test scores as her sons, and purchased a copy of the IQ test to cheat.
