All it takes is a lack of principles, exaggerating a bit, and getting a letter from a doctor. Imagine you have poor eyesight requiring a substantial correction, but you can still drive. That's not a disability. Now, if you create a compelling story inflating how this had an adverse impact on your education and get support letters, you might successfully cheat the system.
I have seen several such cases. The admissions system is not effectively dealing with this type of fraud. In my opinion, a more serious audit-based system is necessary. Applicants that claim to be disabled but that are not recognized as such by the Government should go through some extra checks.
Otherwise, we end up in the current situation where truly disabled students are extremely rare, but we have a large corpus of unscrupulous little Machiavelli, which is also worrying on its own sake.
It absolutely is a disability! The fact that it's easy to deal with it doesn't change that fact.
I would not find it credible that it has a real impact on education though.
If I was the university I would prefer these types of disabled students. Why not:
1. They are not really disabled, so I do not have to spend a lot of many for real accommodations
2. No need to deal with a higher chance (I’m guessing here) of academic difficulties
3. Basically, I hit disability metric without paying any cost!