I am always extraordinarily suspicious of any explanation of a large market movement (downwards or upwards) that is attributed to somebody saying or doing something. The reason is it's fair that there be a few market participants are so uncertain about the value of their assets and their prospective evolution that they react suddenly, but if the market is so shallow that apparently most participants just react to technical trends, then you have a problem.
I wish also to add that the market turning “just about now” had been predicted quite a long time out (30 November) on the public record by the application of the well-known financial model Log-Periodic Power Law (LPPL), whose application to the BTY/USD exchange rate can be read here: https://mynabla.com/2017/11/30/bubble-trouble-exploring-an-l...
So no, bitcoin did not tank because some “idiot swede” said something inopportune. It tanked because the market was totally disconnected from reality (and has been for ages, maybe forever), and because apparently a large proportion of participants are trading purely on technical and not fundamental valuations, and therefore act in unison and pro-cyclically in a shallow and illiquid market. Add to this that it is probably noxious for any economy to adopt a fixed-quantity, deflationary currency, and... there you have it.