Philip Hammond  said the product did not meet the requirements for the use it was put to, and one of the newspaper articles had a shot of the Company's brochure that said it shouldn't be used for building above 10M (?) - those required the RE grade.

UK has always taken a dim view of American style "sue the biggest pockets" lawsuits.

Either K&C specified the wrong product, or the subcontractor supplied the wrong one; hard to believe one or both won't get nailed  - hopefully.