Ann: Update on Columbus Salt Marsh lithium drilling, page-67

Can someone elaborate on this. So according to the announcement made early feb below pump testing and sampling of any aquifers identified would be from lower aquifers as they are shown to be most conductive - so to my understanding this meant it would save time and effort not bothering to sample the higher zones as they would not generate any real results and just cause unnecessary delays (as we already know now through confirmation as they decided to pump test the higher zone for confirmation of brine).
Obviously things had changed with drilling delays and all and did decide to sample test the higher zones but can someone explain why this is the case and did not just announce that drilling is going to take longer than expected and just continue on as originally planned that is to just test the lower aquifers?
Drilling to take 30 days

The drill program is expected to take 30 days and will investigate a highly conductive zone extending from 600 metres to more than 1,000 metres below surface.
A drill rig is on site and following set up of the collar pipe to 106 metres, core drilling to the 1,000 metre planned depth will proceed.
It is planned to drill the hole to 1,000 metres before commencing pump testing and sampling of any aquifers identified.
Lower aquifers most conducive

The reason for this is that the lower aquifers are the most conductive and Reedy Lagoon would like to sample these first.
HQ size core drilling of brine targets will be carried out to maximise core recovery and allow the key aquifer formations to be identified in the core.
This will allow the company to determine the quickest and most efficient sampling and testing strategy.