I am not an ATCO, but I know enough about aviation to spot the flaws in the mid-air portrayed. The rest of the programme was entirely plausible though and overall it was well produced and made IMO. I did not find it scaremongering at all, and for those who are complaining about it, there is a wonderful invention called an off button fitted to most TV sets. At the end of the day, it was drama and all dramas have inaccuracies.
What disturbs me is the ATCOs on here and other threads dismissing the whole thing as rubbish. Not all do, other ATCOs say "the programme was wrong, but such a mid-air is not impossible." They are the ones I would want in charge of any flight I was on, those who acknowledge that the system is not infallible, that mistakes do occur, that computers do fail etc. Those who blindly say "It won't happen" should not be employed in ATC and I would not want within a million miles of a radar screen when I am flying.