Yup. I chucked a multimeter and measured bugger-all resistance between the metal on the ends.
The shielding had braid on the outside, then a bare earth/drain wire, then foil. Each differential pair had foil and an insulated earth wire. I tried both 1m cable and 0.5m cable.
But this isn't indicative of proper shielding at the connectors -- the shield must be contiguous from connector shell to braid/foil. If there is a slot or gap there, you wouldn't be able to measure it, but very high frequency signals can still leak out.
One thing I was thinking of was wrapping a coil of wire around the outside of the HDMI cable to use as an antenna for the RF Explorer. I'll give that a go tomorrow.
Unfortunately I don't have any wireless microphones back at the office to reproduce the issue.
This probably won't do much -- the fields will tend to be polarized lengthwise, because the wires within run lengthwise. A single turn inductive pickup loop might still be illuminating, but rather than placing it over the cable, hold it near the connector ends, at various angles, and see if anything pops up in the 1-2GHz range. Repeat the measurement with the HDMI connection disabled or disconnected, so you can try to isolate HDMI as a source, from whatever trash the equipment itself may be generating.
HDMI signals are high bandwidth digital logic, so they should have plenty of harmonics out there. Between that and the low voltage used in the logic circuits, these cables must be shielded -- to keep harmonics in, and to keep external interference (RFI as well as ESD transients) away. Of course, good shielded cable isn't cheap, and fully shielded connectors aren't easy to apply, so... you can find lots of products out there that work, under lots of normal conditions, but which simply don't meet spec. You may very well have such a cable.
Tim