Sorry catching up as been busy so just addressing some points I noticed further back;
As regards the discussion relating to LL and the nurse where the resus chart which contained calculated drug doses to give in the event of a collapse was missing; the other nurse present knew the doses to give and did so. There was some discussion as to why LL didn't know how to calculate the doses but the other nurse did. The line said by LL which was how did you know that was seen as potentially suspicious or at least called into question her competency. I don't see it as suspicious at all and as soon as I read it I had a feeling I knew exactly what she was getting at.
Some people are very bad at mental maths, especially when put on the spot or under stressful situations. I am exactly that way. I consider myself far from thick but I have a massive problem doing maths problems in my head and have always been that way. I think it's reasonably common too.
When the other nurse said in reply, something to the effect of I just know and I suggest you learn it I don't think she was referring to the ability to actually do the calculations on the spot (although she may have been), I think she meant that she'd essentially memorised the doses through having done it and seen similar charts over many more years than LL had been working at that point.
Yes, people like Carol Vorderman or Rachael Riley can indeed do very fast mental maths but most people can't and even when you think you are doing it you really aren't. If you are asked what ten plus ten is you don't do the arithmetic in your head, you just know the answer is twenty. I think something similar was at work here. So, I suspect that the nurse in question perhaps wasn't actually doing the mental calculations but, rather, simply knew what the correct doses to administer were.
LL clearly does know how to do the drug calcs as she's a qualified nurse so would have had to pass that bit - it's a 100% pass too, I believe. The requirement is to know how to make the calcs, not to be able to do them under pressure. And, let's face it, if it was an easy thing to do then there wouldn't be a piece of paper with them noted on it attached to the bed!