Yep, had it once in a posh home, just finished and the end burst right in front of the customer, black all up the walls and all over a baby grand piano.......
It was on TM as well so alot of power and burning hot..........
She was really good about it, although think she was in a state of shock
Ever since then I've made sure I replace the solution hoses each year and wrap the connectors in case they split.
Once it happens you understand why they call it black death ......
Funnily enough she has phoned today to book her regular clean in, so no lasting damage.....