My DD is only in 2nd grade, so my experience with MAP scores is limited. But I know that hers went way down in the spring of last year, and she was devastated by it - had a full-blown, screaming, crying tantrum. Her reading level was still very high - it just came down from an 8th grade equivalent to a 6th grade equivalent, I think. Her teacher's opinion was that the reading level was a complete nonissue, and she was mostly focused on the tantrum issue (very reasonable, IMO). I think that with the MAP test, if you get a question wrong near the beginning, you can't get back up even if you do very well on all the rest of the test.
I would point out that the score seems lower than expected, and ask if he can retest.
