Helicopter pilot reported participating in a hazardous action.

Narrative

A boat owner; his passengers and I had a pre discussed plan to take a photo / video of him touching the bottom of the skid. We were over water away from other people and homes. At the last minute the other individual decided to grab a hold of the skid. I felt this and immediately pulled away from the boat and lowered him to the water so that he could let go. That was NOT part of our discussions and I would not have approved to be part of that. In hindsight; I would not attempt another action like that as that one decision he made without my knowledge could have ended poorly and I now realize that. I have been a very safe pilot for almost 13 years. I tend to lean very heavily to the conservative side of flying and my plans going forward will be that as well. I am open for any discussions needed to discuss this matter further but you can be assured I understand the complaint and plan to make sure nothing even remotely close like that happens in the future.I acknowledge receiving a compliance brochure from FAA. I also acknowledge a discussions about the actions that took place on Day 0.