Obfuscating one's digital tracks by changing one's writing style is done all the time. He even went overboard by starting sentences with lower case. Seems fishy.
That's only one writing sample from Dorian. It could be a fraud or an outlier. A much bigger dataset would be required to increase confidence in the conclusion. I'd be much more interested in the results from an algorithm designed to compare writing samples, rather than human analysis, which could be put up against control samples and other suspected Satoshis.