I think you're conflating two separate issues: One is the original known impairment that we don't actually care much about, and the other is bullshitting about how the first problem is under-control.

Suppose a real person outlines a viable plan to work-around their dyslexia, and we watch them not do any of it during the test, and they turn in wrong results while describing the workaround they (didn't) follow. This keeps happening over and over.

In that case, we'd probably conclude they have another problem that isn't dyslexia, such as "parroting something they read somewhere and don't really understand."