There is no need for a person to enter a building that is barricaded nor is there a need for a player to enter a police cordoned off zone.
Stop trying to blame the rules for people failing to follow them with their illogical actions.
But that's his free choice isn't it? That's his roleplay choice at the end. And by roleplay, he should get a suitable answer.
Move away or get shot does the trick. Wanna act like a moron and ignore officers warnings? Suspect him and kill him. If he returns after the cops kill him, then its a ban for returning after death, easy.
Again, no ones talking about this situation, nor judging peoples action, only the legitimacy of such rule.
At least that's how I see it.