I agree with the suggestion to get back a scanned copy of the essay.
A few thoughts other thoughts RL
1.Perhaps he'd feel better if he learned more about how the essays are graded. The average reader is spending 2.5 minutes reading the essay.
http://www.washingtonpost.com/wp-dyn/content/article/2005/07/31/AR2005073100963.html The opinion of teachers who have had in him class and thoughtfully read his work should mean MUCH more than the performance on this single short essay.
2.The essay is the LEAST important section on the SAT. Most schools either don't consider it at all or consider it least of the sections. It is mainly used as a confirmation of the student's transcript and submitted essays.
3. He's in 7th grade and for most kids maturity of writing is the last area to develop full maturity.
4. Unhealthy perfectionists focus on weaknesses and don't take sufficient time celebrating accomplishments. Your 7th grader earned a composite score that places him in the 98%tile of college bound seniors!
http://professionals.collegeboard.com/profdownload/sat-percentile-ranks-composite-cr-m-w-2010.pdf Look how few seniors in the whole country scored as high as he did. These are amazing scores. They point to a need to make sure he has access to challenging material for the rest of middle and high school. They also suggest a strong possibility he'd be successful with grade skipping or early college entrance if that is an appealing option.