"The passenger who had checked in the case was located and was asked whether any batteries were in it, to which the passenger responded there were none,"
"The ARFF and Australian Federal Police inspected all four of the bags checked in by the passenger and found 19 batteries intact and [an] additional 6-8 batteries that had been destroyed by fire."
And there is perhaps the biggest problem! Some people have no concept of the danger & will always do what they want to do, even if they are aware that it is not allowed. I don't know if they think they know better than the experts, or if they just feel it is worth the risk of putting everyone's life in jeopardy in order to achieve their objective. It is the same with mobile phones. People don't power them off (I know the rules have recently changed in some countries) & I've even had a lady sitting beside me making calls while in the air. Denied it of course when the flight attendant questioned her.
I don't know how you can effectively combat this mentality.