Bamber's own video below says-
Bonnet was working at HQ Springfield in Chelmsford.
West was working at Chelmsford police station.
So the process seems straight forward: West received Bamber's call. Wrote down the details. Then passed the details onto Bonnet by telephone.
Bonnet then wrote down the details given to him by West
The conversation between West & Bonnet was the period when Bamber was on hold for several minutes.
Bonnet said to West he was sending police officers from Witham to WHF.
West reconnected with Bamber and told him to go to WHF.
Clarification questions here are Was it standard practice for anyone telephoning Chelmsford police to be answered by an officer of West's rank ?
Was it standard practice for an officer of West's rank to ring through the details of telephone serious incident calls to an officer of Bonnet's rank ?
Was it standard practice for both Bonnet & West to write separate logs. West of what Bamber told him. Bonnet of what West relayed to him ?
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I assume the answers are yes. Then this is what happened.
I have never read anything from the CT saying what West and Bonnet say they did was not standard practice by Chelmsford police in 1985.
In today's society, big organisations have switchboard operators who answer calls from the public and then transfer to the correct person. Or put the person on hold while they or get information. Rather like West did with Bamber.
A call to the police where guns are mentioned would result in details being written down in call logs. By both Bonnet and West.
https://youtu.be/Wu6L4Kvql9s