Ultimately, it is the PILOT IN COMMAND who is responsible for the safe operation of the flight. Not the company that owns it. Not the company that operates it. Not the supervisor, the A&P mechanic, the PILOT. He’s at fault here. That bird should never have flown.
Actually the director of maintenance who is in charge of the 100 hour inspections is culpable. Air ambulance and charter flights dont do annuals. Such an operator submits their operating plan to the FAA when issued their carrier certificate. Its up to that carrier to do what they say in their maintenance operations. If not, the operating certificate gets revoked, and hence a settlement to protect that. Most likely fired the director as well.
Look up Carson Helicopter. You’ll see what happens when you fudge the records of maintenance and flight operations. Yes, jail time.