[lmilcin]

That red plastic "mylar bag" isn't what should have been tested.

Red plastic == electrostatic dissipative. It is not good at conducting electricity -- it is still very good insulator. It just has ability to dissipate electric charge fast enough so that it will not accumulate in normal use.

What you have wanted to check is a clear bag with metalized layer (which is silver or gray looking). It should, per my understanding, act as much better faraday cage than an electrostatic dissipative bag. And I would be really interested in seeing that measurement.