How can unplugging a turntable improve digital?

Yesterday, several guys came up from Houston. My digital sound was quite good with the Exemplar 2900, H-Cat P12A line stage, Reimyo 300b amp, Beauhorns, Indra ics, and the IsoClear plug in box and Super Focus powercords. One of them brought along another Super Focus and asked if we might try it on the Exemplar. I had a Harmonix pc on it replacing the Omega Mikro that I had been using. I had Super Focus cords on the power strip, the amp, and the H-Cat.

After we listened for a while, I did put the IsoClean pc in. It was not broken in and did not sound very good, so we listened to vinyl. Later we retried it and found it much improved but still not the equal of the Harmonix. We then tried the Omega Mikro which was much more neutral.

Then one experienced guy suggested that we remove the Garrard turntable from the IsoClean power bar. I was beside the speaker doing this and immediately heard the improvement. Later we put the IsoClean back in with the table still not connected. It too was greatly improved.

Last evening I put the Harmonix in also with the turntable still not plugged in. I really thought it too was much improved and listened again to many of my disks, finding all sounded noticably improved.

I have always thought the "electrons don't know what kind of wire they went through" guys were nuts, but I really don't understand how what is at work here. I am certain, however, that I will never go back. I have found means to plug the table into another independent outlet.