I believe the RT used was as transcribed from the original incidents.
Controllers ARE supposed to wait until clear of conflict before issuing level change instructions - however you study the RT from MANY incidents in the UK FIR and see if that's always the case! When things start to go wrong, and an ATCO gets a TCAS RA on frequency (and/or level bust) the workload can get high very quickly - the temptation to try and 'rescue' the situation persists for what seems like quite a while...until the training/experience kicks in and the ATCO can force themselves to sit and watch what transpires.
Hence the AIC (Pink 194) and recurrent training in the sim for all aircrew to remind us to follow TCAS, even in the event of conflicting instructions from ATC.
So the 'mistakes' were deliberate on the CD, but not in real life - a useful illustration for aircrew of the 'human element' behind ATC.