using a metallic raceway is still allowed and is safe with no changes. Roger
I really don't think that is the question. Everyone does agree that EMT is allowed as the EGC and that it can be safe.
On a new installation either yourself or someone from your company would verify the mechanical integrity of the conduit and it would also be open for a visual inspection by the authorities.
Now we have someone comming in after the fact and useing a megger to test for continuity as a method to verify mechanical integrity. Either this conduit is visible and open for inspection or the EMT is useless as an EGC.
I can touch two pieces of metal togather and get a zero continuity reading but that doesn't mean it's a properly bonded mechanical connection.
The OP is attempting to verify the work of someone else and he can either do a proper inspection of the conduit run or he can't. If it's not possible to inspect the conduit run then he is taking a chance.
If the OP had run the conduit or could see the connections and could verify the mechanical integrity of the conduit run you would see a difference of opinions from most people about the actual safety of this install.
The one thing that wasn't mentioned was if the local authorities were satisfied with the safety of this install ( the inspection department). He has changed the grounding system for this panel and this really should require an inspection and approval.