We seem to agree that it’s dangerous to assert your rights to a tyrannical regime, and that in this case the regime murdered the person peacefully asserting his rights.

I think we are disagreed about whether someone can safely assert their rights before a tyrannical regime. If you could do it safely, the regime wouldn’t be tyrannical. If you “assert your rights” but only in a way that is safe from reprisal by a tyrannical regime, then you aren’t asserting your rights, you are letting the government infringe on your rights.