You can't concentrate too much on "redundant ground". That could just be two green wires.
The fact is 517 says one of these grounds will be the "metal" wiring method itself.
517.13 Grounding of Receptacles and Fixed Electric Equipment in Patient Care Areas.
Wiring in patient care areas shall comply with 517.13(A) and (B).
(A) Wiring Methods. All branch circuits serving patient care areas shall be provided with a ground path for fault current by installation in a metal raceway system, or a cable armor or sheath assembly. The metal raceway system, or cable armor, or sheath assembly, shall itself qualify as an equipment grounding return path in accordance with 250.118. Type AC, Type MC, Type MI cables shall have an outer metal armor or sheath that is identified as an acceptable grounding return path.
(B) Insulated Equipment Grounding Conductor...
Sort of eliminates any plastic wiring method huh?