Friend or career

Sarah is a registered food Laboratory Scientist and has just been promoted to the head supervisor of of the pathogens department where she has been working in for 5 years. throughout those 5 years she has become good friends with everyone in the pathogens lab. David and Sarah are the closest in the lab but David has an issue following procedure and despite all the friendly Waring from Sarah he still refuses to use proper aseptic techniques when handling the samples.
with increasing cases of cross contamination since Sarah was appointed the role of supervisor it seems her promotion may come to a premature end unless she solves the problem with David. After multiple warning her best option is to fire her friend David however in the process she may lose a close friend and also the support of the rest of the crew.