The fact that this can happen when it was clearly recognized by the authorities he was in danger, should make us all concerned - I am not saying this out of concern for Williams - that it suggests that someone allowed this to occur (note: the guy who did it had associated with corrupt police)
Who had something to lose from what Williams knew was not likely to be the nicest person and I don't feel great to know they seem have the power reach Williams despite authorities "best efforts" at security