From the FAA TCDS
NOTE 15: 1-pilot IFR is approved for Models S-76A, S-76B, S-76C, and S-76D when appropriately equipped and operating in accordance with a flight manual or flight manual supplement that allows such operation. For Models S-76A, S-76B, and S-76C, 1-pilot IFR operation requirements include installation of an SPZ-7000 Digital Automatic Flight Control System by STC or an SPZ-7600 Digital Automatic Flight Control System by STC or as optional equipment. The following Honeywell Flight Manual Supplements relate to 1-pilot IFR operations with the SPZ-7000:
So the aircraft could have been IFR, depending on the equipment
Operations as noted above
HTAWS is required under HAA, 135 Subpart L Helicopter Air Ambulance Equipment, Operations, and Training Requirements