ocean, compared to me, i think you came off as rather lucky. I believe it was a couple of years ago when I replaced a black cuke with another cos it was too big. Only a few days later, my entire tank was wiped out, leaving only a few corals. At least a flame hawk, yellow tang, sailfin tang, 2 ocellaris and a dwarf angel passed on. The black cuke was never found.
Interestingly, the first one which did ok in the tank had little pricks on its body. The one with wmd felt velvety to the touch. Was tempted to get another one at ML recently cos of their small sizes. But they felt exactly like the killer one i had, so it was an awful reminder and I choose to maintain my tank cuke-free.
BTW, it was a mere 2 hours between ok and massacre.