How many 'wire' EGCs were at the outlet?
And are you sure that you had a redundant ground EGC rather than an isolated ground EGC?
If it really was just a redundant ground, then it should not really have mattered which was which as long as each of the two was terminated to a different point on the receptacle and both ran independently all the way back to the ground bar of the panel that fed the circuit.
If there were more than two wire EGCs, then it would potentially matter which was which. And it would matter which one was the redundant ground in that it might not be connected to as many outlets and would be less likely to end up carrying fault current originating somewhere else. As I understand it, the two ground paths should be kept separate (or at least redundant) from the receptacle all the way back to the panel. (But see following definition, which muddles things a bit.)
517.2 (2011):
Patient Equipment Grounding Point. A jack or terminal that serves as the collection point for redundant grounding of electrical appliances serving a patient care vicinity or for grounding other items in order to eliminate electromagnetic interference problems. [99:3.3.141]
as contrasted to 250.96 (2011):
(B) Isolated Grounding Circuits. Where installed for the reduction of electrical noise (electromagnetic interference) on the grounding circuit, an equipment enclosure supplied by a branch circuit shall be permitted to be isolated from a raceway containing circuits supplying only that equipment by one or more listed nonmetallic raceway fittings located at the point of attachment of the raceway to the equipment enclosure. The metal raceway shall comply with provisions of this article and shall be supplemented by an internal insulated equipment grounding conductor installed in accordance with 250.146(D) to ground the equipment enclosure.
Informational Note: Use of an isolated equipment grounding conductor does not relieve the requirement for grounding the raceway system.
The first may be required in hospital patient care areas, while the second may be used in lab areas or for other sensitive electronics. Its usefulness when other wiring has been done correctly has been debated.