Sounds to me that those scores are off. I don't believe a kid who can read at age 2 is just a high achiever. My son is DYS and way above the DYS IQ cutoff and he didn't read until 2 1/2, to put help put your son in perspective.
I don't think that early reading milestones can be reliably mapped to IQ. I also think that high working memory could well be an aid in learning to read.
If I were you I would completely ignore those results.
I wouldn't completely ignore them. There's no way to fake a high working memory, for instance. The presence of high scores also means that there was likely not a rapport or anxiety problem in general for the test. Perhaps there was an attention span problem, since the test ran long-- but overall I don't see why one would
completely disregard the results, just because they are different from expected. That's why people test, to weed out the subjective.