As an ex-member of the emergency services I can state quite categorically that despite being not only verbally but physically abused on many occasions I NEVER used foul language even to those who assaulted me.
I did so LATER out of their hearing but NEVER to their face(s), even though I was sorely tempted on many occasions.
I know that we are all human but there is no excuse for using expletives to those you are meant to serve, and especially, as in this case, to people in great need of your help and expertise. It only makes the job harder for the vast majority of decent people who are then tarred with the same brush because of the unprofessionalism of the few!
The only thing I can think is that those concerned may well have been under great pressure, the emergency services are all the time. However, many members of the public never come into contact with Police, Paramedics or Firefighters, and if or when they do, the first impression is usually the one which creates the greatest impact.
None of us is perfect, though! Hang on - me halo's beginning to slip !!!