Sounds like you've either misunderstood what may have been said, 3rd hand news never travels well, or the engineer isn't as up to speed as some are ??
Firstly, for info, we can't just start mending people's lines ad-hoc. We have to have an audit trail. Secondly, our systems automatically pick up if there is more than one fault reported in a particular location. However, it needs the EU's to report them individually so our systems 'see' the high fault volume on a particular node. When it does, it 'commons' all the faults together and only one of the faults is given to the engineer as a 'Lead Task'. He will be contacted by the 'Commons Control' to be made aware of the details of the other faults.
The bit about being trained on antiquated 20CN equipment is pure fiction. The lay-out and connections of 20CN is exactly the same as 21CN. Even with that in mind, if the faults are 'commoned' to an 'Exchange Line Card', then the engineer will have to pass the job back for BT Operate to pick up the trail. They own the equipment, whatever ilk it may be.
The crux of the matter is, you could have 50 folk in your locality whingeing about loss of service, but if only one person complains, it looks on the face of it to us as a single stand-alone issue.