The paper is written rather... colloquially. Not necessairly a problem. But it seems mostly concerned with telling the story, and that a huge buyer in the market causes prices to go up. That's not market manipulation.

However, there is also the claim that the buyer did not actually have to pay for the BTC they bought. Well, that's certainly a (very strong!) form of manipulation, but it's not what people traditionally mean when they use the phrase. There is normally an expectation that you have real money and are following exchange procedures, but simply behaving in a way that is frowned upon or considered unfair/detrimental to the reputation of the market. As far as I can tell, people are still worried about traditional manipulation in Bitcoin markets, for things like marking the close. The behaviour described here is more akin to hacking/traditional fraud - it is not zero-sum.