He has not played well on the field . It is well documented. A reading disability is not an excuse for a record low test score. If his disability is that severe, how did he pass any if his classes at LSU?
If you want to take the score as valid then fine. As has been noted he has a reading disability and declined to take the test. You can characterize it however you like but there is a clear cause and effect that doesn't include him acting like a 5 year old. Players decline tests all the time.
I think if you want to call him dumb then you should be talking about him busting coverages. I know he got beat on routes but no serious mental gaffes stand out in my mind. Do you have any examples?
I also think your comments on his play are hyperbole. He held more than he should but it wasn't just him that was getting thrown on against the Bears and Patriots. Carr got most of the single coverage and really did get torched a ffew times and opponents attacked the middle of the field a lot. That is where the free first downs were.
Claiborne's sin was getting beat out by Orlando. Scandrick was the second best player on defense last year. There is no shame in being beat out by play like that unless you are the 6th overall pick I guess. That speaks more to how Scandrick played than it does Claiborne anyway.