The relevant categories are not civilians and non-civilians but public officials and ordinary people. Public officials often have powers and duties that go beyo

The relevant categories are not civilians and non-civilians but public officials and ordinary people. Public officials often have powers and duties that go beyond those of ordinary people, and police officers are simply one special case of that. Also, in jobs where people's lives are at stake, there are often situations where you may commit a crime by refusing to do your job properly. If a lockdown has been ordered, it's plausible that the situation is like that, and any official with police-like powers can reasonably stop anyone trying to leave. Especially if the person trying to leave is also a public official.