I think that the cleave change was due to it killing tanks. There were times when we attempted it that the thing would one shot our tank, and she is an experienced tank that was mostly black hole at the time. After that it was a wipe.
I am very sorry, but if she is very expierienced tank, she should have know how to use interrupt...
on second note, (i'm usualy doing puzzle) I was asked recently to do tanking since other tank wanted to learn the puzzle in case I'm not there, and I absolutly forgot that there was anything to interrupt on SM, and barely seen my hp going down from first cleave, and interrupted all others.
and this was columni jugg alt tank, can't think how it could one shot full BH tank.
unles you are talking about HM EC, in that case, I'm afraid it will still be killing her (on side note, again, cleave on HM doesn't do much dmg either)