My RBTA has killed a coral. I had an encrusting coral on the rock, and the nem took up residence about 6" away. As the nem grew it started touching the other coral and stung it to death over a course of many weeks.
If you keep corals out of there way while they settle in, then give them a wide enough safe zone as they grow, then they are fine with corals.
If you keep corals out of there way while they settle in, then give them a wide enough safe zone as they grow, then they are fine with corals.