Absolutely, well said G/ Biscuit. The PLASTERBOARD ceiling and walls have been DAMAGED by water. It doesn't matter what that the damage is, both should be re-placed. The ceiling is being replaced because it has been damaged, the wall/s should be replaced as well, because they too/the plasterboard have been badly stained/weakened by the water leak caused by the plumber. Why should the stain/damage be covered up with a coat of sealer. Why should Elligabe be the one to lose out? She wants her property to be the same as it was BEFORE the plumber started, as she said, why should she have to cover over stained, possibly damaged, plasterboard. All the water damaged areas should be re-placed,, like for like.
Again Elliegabe, keep the plumber informed of what you're doing/taking it further, to the Insurance Ombudsman.