By "the Senate" you mean the Seante president, right? Because here is what he had to say about his decision:
Senator Hogg said: "There is no question that the matters raised by Senator Kroger are very serious ones.
"The freedom of individual members of parliament to perform their duties on behalf of the people they represent and the need for them to be seen to be free of any improper external influence are of fundamental importance."
He said the matters raised related directly to the issue of parliamentary privileges and allowed Senator Kroger's motion to go ahead.
Hear, hear! Couldn't agree more and I imagine neither could the Greens, transparency is essential in a functioning democracy.