I keep coming back to this part of your comment and I think its the most useful piece of non-classified data we have. Lots of possibilities of what happened here, for sure. The one sure conclusion we can draw from this is that SpaceX does not think the Falcon 9 failed. If they thought that there was an issue with the Falcon 9, you're correct that that would have caused a stop of the Heavy launch. Now, its possible SpaceX is wrong and there was an issue with the Falcon 9, its possible there was an issue with the payload or the payload separation or even possible that there was no issue at all. With all of the classified information on this one, we probably won't know for sure in our lifetimes but we can say one thing for sure. The people who do have access to the classified information do not think there was an issue of enough magnitude to delay the Falcon Heavy launch and I think that speaks volumes. If the mission had failed I think we would see at least a brief pause, even if SpaceX quickly decided that the failure was not theirs and continued. The fact that they are pushing on leads me to lean strongly in the direction of the mission actually being a success.