I would agree with that. It is not the soldier's duty to investigate on the spot who is who. The soldier's duty is to force the other side to drop their weapons and surrender. The rest is handled by civilian prosecutors, judges, and lawyers. It does not even matter if Assad's regime will preside over the trials. It's just too hard to explain to the court why someone "had to kill people" for a political cause.
You are correct!! The mosque in Moscow!! Just the other day.