Another true case.

A man buys a bag of coal and puts it on his fire in his house. Amongst the coal was a detonator. It blew up taking out a potion of his wall and making a bit of a mess in the process.
He tried to sue the coal merchant under the Trade decription Act and lost.

The defence said that
The merchant sold a hundred weight of coal to the man and thats what he got. The coal was supplied in accuratly weighed bags and the coal did as it was supposed to do and burned.

The detonator was a free gift.
It did what it was supposed to do and caused small explosion.

So under the Trade Description Act both items did as they were supposed to do.