I have to say that I'm not giving that one much credibility, so far anyway. That bit about the large amount of oil dripping out of the vehicle just doesn't jibe with most of the other reports I've seen on this cracked NA head issue. As you know, when the head cracks and oil starts dripping on the exhaust manifold, the burning oil odor and smoke are immediately apparent. It's hard to imagine anyone driving even a mile or two, once that condition starts happening.
So, how can it be possible for that much oil to exit the head from a crack, in what must have been a relatively short amount of time? And it's particularly difficult to imagine, given that the underbody plastic panel is going to catch and retain most of it, until (some of) the oil has enough time to slowly make its way through the small access panels. But a good portion of the oil would probably just spread out in a thin layer on the panel. So a significant amount of oil on the driveway is the most difficult part of that story for me to believe.
Now that said, I'll concede that it's POSSIBLE this particular one was a section that blew out of head, instead of just the typical crack. I've never read anything like that before, but I suppose it can't be impossible either.
And the other thing about that thread is that the OP quickly answered one question, but has not come back since then. I'm going to reserve judgement until more time goes by, but right now that one is in the doubtful category for me. However, I will edit this post, if that OP comes back and proves that what I wrote here is not correct.