Experience
Ref Swamp rats comment about experience. There are certain limitations that Mr Cessna has written down for a C206 and no matter how experienced you are if you want to fly outside of those limitations then you will crash eventually. Not saying that this was the case in this accident but saw so many non standard inventions that guys would come up with for what they thought was the best way to operate a 206 in my time there.
I was horrified to see that a certain operator out of there is starting or has started a training school. What on earth will he be handing down to new pilots. Very Scary!