As I thought, the Rigel 288 & GMC Secutest SIII are not compliant with IEC60601 requirements for protective earth measurements. (They use a DC 200mA system).

http://www.rigelmedical.com/downloads/0008-Tests-available-on-Rigel288.pdf

Could this be that Mike is trying to raise the profile of IEC 62353 standard, via an alternative route (as per his previous posts?).

The IEC 62353 standard has not been universally adopted, and has been extensively discussed on this forum previously.