You've received a great reply above. I'll just add three thoughts:

1) Is there a reason why the child "was not properly medicated at the time of testing"?

2) You mention an IEP and a 504.
There are differences:
- wrightslaw Wright summary
- wrightslaw Ask the Advocate
- Understood.org - side-by-side comparison

3) In preparation for any potential advocacy efforts, check your State laws and your school policies. Basic advocacy info here.