Sprinkler test and it rains

Last Friday as the plumber tested the sprinkler system a gush of water started to pour out of the kitchen ceiling- I ran upstairs and saw water pouring out a hole in the laundry room wall!!!
The sprinkler heads were fine but "someone" had left the airing pipe open behind the sheetrock!!
At least they figured out what the cause was and fortunately the laundry room and kitchen hasn't been painted so we are ok.
My heart sank as it was happening but better to find out now then later.