Yeah its unfortunate. I have not had a death caused by this but I did have a particularly flighty purple tang years ago that constantly would have scrapes and marks on it from this same thing. Working at a lfs off and on for years I saw it a few times. We would typically get shipments from QM and continue the qt process and in a few weeks we would move them to the sales floor. It always seemed while in the backroom qt they would be fine (they = almost any of the fish we got) but once on the sales floor some would get very skittish the wrasses would start jumping and tangs, angels, and butterflies start darting and unfortunately there would be a few casualties. This is one reason I think certain fish even if it can possibly live in a say 4' tank bigger is better. Sometimes they just go for that flight response, possibly for no real reason we can see. My fish with the purple all got along fine there was no aggression just sometimes that purple would just freak out usually at feeding time and being a standard 120 it didnt have that far to go. I eventually set up a 6' 125 and moved him to it and it still would do it but at least it was less damage to the corals (euphyllia dont like when fish slam into them sps fare a little better only because I dont think the fish wants to get impaled or maybe the damage to the coral is just lessened).
