Oh come on, you know the score. The people who write these books are not the people who carry out the job. I see this in my job daily.
The person with the crimps, would of gone to his local halfords / motorworld and bought the car set of crimps designed for 12v. The crimper is poor, and then the crimps are even worse. If the 6mm cable dont fit into the connector, he would trim it down. Ive seen many dodgy crimps that have been taped over. The DIY'er aint gonna pay £19.99 for a rachet crimper and the correct crimps.