The purposeful destruction of infrastructure is an inexcusable war crime.
But "the west" did not stick a sword up Gaddafi's butt -- that was his own people, enraged by the actions of a totalitarian.
"The West" did not wander into Libya and and lynch a so called world leader who only wants norms followed when said lynch mob has formed.
To kill in this manner is a crime, but it happens when so many laws and norms have been broken it's more akin to manslaughter, more akin to a concentration camp victim losing their temper, seizing a firearm, and executing their former captors.
(As they say in America: "Fuck around, find out.")