I imagine that if the person were bonded, they then carry a possible static charge of the helicopter in flight, and could expect a shock when set onto the ground during normal operations.
This occurs when winching and is dealt with by having a length of wire (static discharge lead or zapper-snapper) attached to the winch hook that touches the ground first, you could easily do the same.
At the French National Helicopter Championships in 1990, I watched a HEC demonstration with a mountain rescuer and a dog on harness, suspended below an Alouette - there were actual lighting strikes hitting the ground around much of the airfield but they carried on - no-one got fried so perhaps your regulators are being a little over-cautious.