Seeing how the airlines operate, it is possible to load someone elses bags with stuff. I don't think baggage handlers are watched that closely here. If her bags were not locked (as I usually do when travelling) then she may well have been a victim. I think if she is a victim, the perpetrators could of at least split the packages so as to be only 2kg each therefore not impose the possibility of 'death' on the victim.
If she did do it - then silly her...
I personally think there is enough 'reasonable doubt' at the Australian end, but whether they consider that sort of thing in Bali?? It's all such a shame but that's how it is...