Here's hoping that independent testing gives you the answers you need. Talk to them, offer them copies of past results if the psychiatrist thinks it's a good idea, because they may be able to work with those and maybe concentrate their vision on those areas most of concern.
That major discrepancy in the digit span score worries me. But there are other variables here, notably WHO gave him the test. And frankly, from my experience, tests done in the school environment (by either a school counsellor or someone brought in by the education system) are always suspect, in my book.
An example - when I was at school one of our science text book series were written by a Professor Harry Messel, a Sydney University Physics professor. They were very readable, I found them entertaining as well as informative. But they weren't always accurate. We were taught to double-check information. And our teacher's notable comments one day said it all, and were quoted: "I've got you lot well trained. When you notice a discrepancy between Messel and another text, you immediately assume it's Messel who's wrong."
In the same way, a discrepancy between a school-based test and one administered professionally - I would be assuming the school-based test to be the equivalent of Messel.
If you have a large amount of data points and you're plotting them on a graph, with enough points you begin to see a pattern. But if one point is stuck out somewhere very different, away out on its own, we are taught to ignore it as an aberration or anomaly. Clearly something went wrong in that particular measurement.
The only other explanation is a deterioration in digit span, which should be fairly easy for a professional to double-check.
Within one test, are there large discrepancies? If so, what are the sub-tests on the top and bottom of the scores? And what is YOUR gut feeling, concerning difficult child's true abilities?
Marg