The shooter says he hasn't noticed this in the viewfinder. It only seems to come up after reviewing recorded material. On one instance we were recording directly to FCP using the HDSDI out. It was never recorded to tape and it showed the same problems.
Because Varicam is a digital camera, it's less susceptible to "ground hum", but this effect could still be introduced by monitor connected to AC and/or analog audio connections. See if you can reproduce the effect with no monitor or audio connected before sending in to Panasonic.