The arguments for Nick being Satoshi, other than the fact that he's one of the few dozen people with the skills and interests to do the design right, came down to
- "he uses this set of technical terms, and so does Satoshi" and
- "he also uses a few other sets of phrasing in his academic papers that Satoshi uses" and
- "pay no attention to the US-vs-UK spelling differences."
But the technical terms that the current speculation mentions are all standard terms in the field, like "trusted third party" (which was probably used more 5-10 years ago than today), "timestamp" used as a verb (common), "timestamp service" (there have been some done by crypto people like Stu Haber, and it's a well-understood concept.) The general language choices are mostly using passive phrasing like lots of academic papers do; you could argue that Satoshi is probably either an academic now, or has been one once, or learned English in an academic environment (i.e. learned it in college if he's actually Japanese.)
It's more likely that Satoshi is really Nick than that he's really David Chaum, but unless Nick admits to it in public or suddenly starts using his billions of dollars worth of bitcoins to build an Evil Genius Secret Headquarters, it'd be rude to hassle him about it even if you think it's true. (Also, in the latter case, you'd be saying that Nick isn't capable of maintaining his disguise as a mild-mannered academic while also secretly building his Secret Headquarters, and saying that "We can't tell who's really building this Secret Headquarters so it must be Nick!" doesn't really cut it.)