The international politics and law requires a net set of commitment from nations to be sensitive to one another's rule of law and diplomats should be more sensitive in the discharge of official duty on a foreign land.
Under the guise of immunity no diplomat should be allowed to shrug off from his/her liability and a crime under which a common civilian is punished under a country’s criminal system. The notion that "No one is big enough that he/she cannot be tried under the law" should be widely upheld and observed across the world.
The role of the diplomacy is to make people's life better across the national and international borders without sacrificing innocents’ life. The highly debatable issue here is to define what constitutes a petty crime and rarest of the rare crime; but to shield diplomats under the false notions of immunity is highly uncalled for and it requires thorough relook of international politics and diplomacy and reframing of international laws.