SLF speaking.
Good work by the BBC.
Whilst presuming that all controllers are doing their very best, I presume that most major airfields around the world have this problem.
I have presumed for some ten years that these problems are higher at EGLL and EGKK due to the reduced level of interest that the CAA takes in the running of operations since the changes introduced by the Thatcher govt.
The CAA have consistently allowed more rotations to be booked into EGLL than it can reasonably (that lovely English word) handle. NATS have, in my personal opinion, consistently accepted more traffic movements in the London area than can reasonably be handled. I presume that, at some time, two a/c will meet over London. I presume that the chance of this happening is slight but GREATER in London that it might be or should be.
I see the actions of the CAA and NATS as being entirely typical of modern govt in the UK, as instigated by the Conservatives and enthusiastically continued by the neo-Tories, otherwise known as New/Labour.
Can anything be done? Yes, cut back on traffic movements until new runway capacity is available. That will not happen. And, if more runway capacity IS provided, then the numbers will be increased further. This will be done because the lack of prangs will 'prove' that what they are doing is safe, so they can have more movements with another runway. Rather than the keep the numbers the same and increase distances and timings.
The only other thing to do is have more ATC staff and reduce their workload and time at the screen. Again, this won't happen and because of the commercial pressures. Which ... is where the problem started!