[evan_au (OP)]

Astronomers have discovered a star whose magnetic field flips 10 times faster than the Sun.
This star has a "Hot Jupiter" planet on a 3-day orbit, which they speculate is dragging on the star's outer layers, causing internal differential rotation which drives the star's magnetic dynamo more strongly.
http://www.ras.org.uk/news-and-press/224-news-2013/2312-star-tau-boos-baffling-magnetic-flips

It is known that Earth's core rotates faster than the crust: http://www.columbia.edu/cu/record/archives/vol22/vol22_iss1/Core_Spin.html
Could the Earth's Moon with a 27-day orbit be causing tidal drag on the Earth's oceans and crust, causing differential rotation between the inner core and the crust, and driving Earth's magnetic dynamo more strongly?

[It wasn't clear if this question should go in Geology or Astronomy...]

[Pr. snoerkel]

We know that the Moon drags on Earth's crust  and especially on the oceans by tidal effects and that causes the rotation of the Earth to slow down. It has been proved that the days were shorter in the distant past. Since the core of the Earth is not glued to the crust, the core can move independent of the crust.
So, in short, you must be right