How do you feel his sensory concerns are impacting his education and experience at school otherwise (ie. ability to relate to peers, participate in recess appropriately, eat lunch with other children without incident, etc.)? If you have concerns which you feel were not addressed in this evaluation, then you can request an Independent Educational Evaluation (IEE). The prior evaluation is the PWN for that request, which is why the case manager gave you another copy of the evaluation.
However, while that is moving forward, after your request for an IEE is made, what are you hoping to gain for your son that he doesn't already have? Did he not qualify for an IEP at all? How do you see him struggling at school?