Doing things that are not part of your job description

I found this story today about an ambulance crew stopping on the way back from a job to deal with a horse that was running loose on a British motorway.

That's what I call taking on a responsibility that has nothing to do with you, but improves the circumstances of others that you know nothing about. They could have driven away, treating the horse as somebody else's problem, which might have then led to a car smashing into the horse, and the driver and passengers requiring either an ambulance or a hearse as a result.

I hope the crew got a lot of satisfaction from doing something that was not in their job description, but prevented a potential catastrophe. A gold medal effort of not somebody else's problem.