Ann: Maiden Drill Results at Mulwarrie, page-4

Interesting that two holes 4 & 13a deviated downwards and will be re entered and extended.
Deviation is either from ground conditions e.g. fractured rock, voids or contact between two different rock types, or it comes from less than optimal control of the drill rig.
I am not a driller nor am I criticizing the drill crew, however I have been around a lot of drilling rigs and drillers. Good experienced drillers are able to tell what is going on at the drill face by listening to the rig, monitoring the guages etc, much like any other experienced operators of machinery. All that takes time and the last few years have seen many new drillers step onto the platform. Often the reason for deviation is from pushing the drill string too hard. The problem is the driller doesn't know about the deviation until the camera shots are taken, which can make correcting the deviation very difficult if not impossible. Camera shots being the term used for downhole surveys of azi and dip etc.
Also of interest is the deepest hole is 13a, which indicates it is a redrill of hole 13 which has been abandoned for some unknown reason at an unknown depth. Often this is caused by collaring issues and associated air loss.
We shall know soon what the extension drilling shows and the sniff at the EOH is intriguing.