I think it would be a little premature to diagnose a malady such as RTN without knowing any history of the coral considering none was provided, especially given that particular necrosis and/or degeneration of tissue is uncommon other than corals with thin tissue (Acroporiids, Pocillipora spp., Galaxia spp., etc). In addition, rapid tissue necrosis can consume, if not do consume, entire colonies within hours/days leaving little hope for offensive remedies other than fragmentation. However, the first thing that did come to mind was sediment damage. These corals are often mistakenly placed upon substrate where the surrounding tissue is smothered. You can see the tissue margins around the "points" of the skeletal base. Where was this coral located at the lfs
and what other corals, if any, were surrounding it? As for the holes, possible predation from a fish, depending on what else was in the tank where it came from, polyp extrusion, or a boring predator.