I get the point in your scenario. The simple matter of "degree" in this case might be simple but it is very big. First of all, i would say that your scenario is

I get the point in your scenario. The simple matter of "degree" in this case might be simple but it is very big. First of all, i would say that your scenario is unrealistic. It is made up and it would never happen in actual real life. First of all, what psychopaths would leave a dying man, woman or child like that? Also, how would these ambulances get customers? Thirdly, who would sign up for their ambulance service? Yes, if we accept your premise of a society where this psychopath ambulance service has a monopoly and everyone is forced to use it, then sure, it is exploitation. But on the other hand, someone with authority has therefore sanctioned this psychopath monopoly ambulance service. Where did this authority get this mandate? Democracy? If you want to argue that this scenario would happen on the free market, i would like to see your arguments to why this ambulance service would still have customers. If you control the premise of the arguments, it is easy to "win".