I should note that I have seen dysgraphic presentation in quite a few students diagnosed with ADHD, especially the more severe ADHD learners. I suspect that the pathway to dysgraphia may be different than in dysgraphia without ADHD, but the end result is much the same.
Also, remember that the fine motor demands of the PSI are much less complex than those involved in letter formation (especially on Symbol Search, which is just a slash). And your DC was tested before age 8, which means that even Coding involved simpler symbols.
I would agree that another comprehensive evaluation may be indicated--with a broad look, rather than preconceived notions. Many of the diagnostic possibilities would not have been evident at the time of the earlier eval, simply for developmental reasons, or because of lower age-expected demands.
