I just asked my father about Telstra in the 90's and he said that exchanges, even the small, suburban ones were only accessible to staff who worked there. Most exchanges only had a few staff. Most technicians never went to an exchange - they received their jobs via a remote office.
For those few staff authorised to access an exchange, access was via keypad and all entrances were logged electronically at a central base. I didn't get to ask whether there were cameras installed at these exchanges as Mum didn't want talk of such dark things on Christmas Day but I would doubt there were cameras in those days.
To tap a phone from the street one would need to access a pillar (not a pit) and know which two cables to locate. This would take knowledge and time as there are many cables in a phone pillar.
Dad was scathing of the idea that BE might have tapped a 'phone box. He doesn't believe the young techs were well trained enough by the 80's and '90's to know which pair of cables to locate. By the 90's Telstra was being privatised and training was going by the wayside, in his view.
Not many Telstra techs worked at night, not even in the telephone exchanges which were all automatic by then and in my youth (70's and 80's) I don't believe my father ever did night shifts. He did work in exchanges as he was a Supervising Technical Officer.
As an adult, I've only ever seen Telstra techs on the street working in the daylight hours.
Dad tends to think the CSK used quiet, open areas like the Karrakatta Cemetary to do his nasty deeds in and I tend to agree.
I think CSK was responsible for the abandoned Lakeway Drive-In attack (even though it was not reported to police, I have no reason to doubt it occured).
There were so many quiet, dark, remote spaces out that way that he could have taken his victims to...Karrakatta Cemetary, Lakeway Drive-in, the Fremantle wharf area (massive car-parks around there)...beach sand dunes.
Make of this info what you will. Just my opinion, as always.
