This has nothing to do with the earth rotation and the Coriolis force. It’s purely for the suckers.

Here’s the trick: notice how he pours the water into the basin on each attempt. You don’t see it for the original one; it’s been sitting there for a while and has settled while he does the little demo with the compass and probably some more lecture. But he pours the water off-center for the next two experiments, so there is already some rotation of the water, and the result is exactly the direction you’d expect from the pour. When he pours on the left side of center, it drains clockwise, and when he pours on the right side, it drains counter-clockwise.

One, of course, should do this with both pour techniques in the same location to be a real experiment.