To put in 2 cents from a different direction: I am an avid sailor. I also have had a few hours at the controls of a glider and a single engine aircraft, and many hours at (home level) simulators. I have some kind of background in physics and aero/hydrodynamics.
Yes, I can land a small single engine aircraft. Maybe with a bit of coaching from the other seat. And I know, in principle, that a big aircraft is physically not fundamentally different.
However, I very much doubt I could do any good at the controls of such a big jet. And this view does *not* come from my experience with small planes, or the sims, but from sailing.
Entering a berth with a yacht (say 30 feet & above) is not that easy. I have had my own classic boat now for 12 years, and in unfavourable conditions, I'll still sport a 180 bpm pulse, and have botched a few approaches. Of course, this does not compare to landing - on the boat, the worst that can happen is the equivalent to a fender bender. Still.
Sitting in the harbour, one of the most entertaining things is the so called 'harbour cinema' - mainly charter or otherwise inexperienced sailors trying to get berthed, and observing their blunders and mishaps. (Don't worry, I'm one of the first to jump on the jetty and lend a hand!)
The lession this taught me is that unless one is profoundly familiar with a) the craft, b) the settings (harbour/airport), and the conditions (wind!!), the chances for mistakes are *huge*. How can I assume I could pilot a big jet safely to the ground when I don't even manage at all times with my very familiar sailboat? Or would I attempt to guide a supertanker through the panama locks just based on my small craft experience?
Definitely no.
Likewise, getting back to the OP's question - in that situation, would I attempt to put down the plane in one piece? Even without a PPL? Hell, yes. But I'm not delusive - I guess my chances would be very,very slim. But at least I'd go down fighting!