After thinking this over and realizing the immaturty of Hunter A:
Hunter A, seeing B climbing in,continues to shine his light at B, and also claps hands, coughs, and makes other loud obvious noise
I would have stayed for awhile and then set up elsewhere.
At least Hunter A must have know it was ok for Hunter B to be there. We once kicked a family off of 5,000 acres b/c no one told us that they were invited guests. Once we knew, we let them back onto the property and welcomed them. Embarassing!