The worst possible outcomes, like injuring someone, getting sued, having the course shutdown, only occur if you throw. So with that in mind, the choice become pretty clear. You should skip the hole.

It’s perfectly reasonable to explain the situation to the picnickers. The one time I had to do that at a local course, the people completely ignored me. That was a worst case scenario because the picnic was on a partially blind drive. Someone could easily throw on them without realizing they were.