This loss of separation implies that it is the controller(s) sole fault. Yet many incidents of reduced separation originate from pilots not responding quickly enough to speed reductions, heading changes and altitude changes. Air traffic control is a service to pilots - the ultimate responsibility for the safety of each individual aircraft belongs to the Captain. If he or she deems the separation to be unsatisfactory, then he/she should immediately seek alternative action.
This is one incident in thousands of routine approaches in a terminal area serving very busy international airports. Don't sensationalise it -and why did "Andrew" not voice his concerns as an active controller?