While not an Attorney, I can almost guarantee that anyone holding open a crossing gate, which can be seen as encouraging a rider to pass through, will end up in court. Under the best of circumstance they spend a bunch of money defending themselves and under the worst they spend time in jail. In many states you can be held partially liable for waving someone into traffic -which was not clear- and creating an accident.
In both these cases, we would think that they should have known, but liability gets spread around like warm butter on hot toast.
I'm not trying to argue, simply make someone reading this think twice before doing something like this.