My suggestion is to ask you guardian spirit about it. If they were "upset" about the pendulum/your friend, there must have been specific reasons. Learning more about what those reasons are will give you a better idea of what (if anything) you should do. There's a possibility that the aventurite is completely incompatable with your friend (I doubt this would make a guardian scream, though). Or maybe it was a warning that your friend should not explore pendulum usage at all, but especially not with aventurite. It could be warning you that your friend needs more spiritual training before experimenting with a pendulum. Or it could simply be that the combination of aventurite and your friend puts off an energy that is painful/incompatable to you or your guardian. Best to find out what caused that reaction, if possible.