You keep lumping the west into one yet the nations that make it up adhere to very different ROE. Does Israel class as the west now too?
You're over egging your sudden revelation though. For example, uk rpas units operate under a legal framework with several ladders in the approval process to execute a strike. Simply put, the safety net is there that it wouldn't hold up in court because it could be proven that every step possible was taken to ensure the strike was legal. Should it so happen that a civilian was caught in the strike it would be easy to prove that before the weapon was released it was done so beyond reasonable doubt that it would not cause civilian death. In the case of MH17 being shot down, I'd suspect it would be harder to prove that there was no doubt. I do believe it was mistakenly shot, as opposed to intentionally, but I don't believe the operators took all the necessary steps and precautions to remove all doubt. They're russian after all
Guess how they avoid any of this anyway? Continue to outright deny it, which they are.