Gloopy,

I know the Delta crew wouldn't land on a taxiway full of aircraft.

However, all normal safeguards were bypassed when the pilot began the flare over the taxiway. At that point, the landing crew would be powerless to prevent an accident had another aircraft entered the eastern third of taxiway Mike. It is not a major stretch to say that this would have been a disaster.

At that time of day, a taxiing crew "clearing left" would have thought the distant aircraft lights were landing on the parallel runway, and a good chance they would have proceeded onto the taxiway.

It was pretty much dumb luck that no other aircraft pulled onto the taxiway during their landing roll. That said, I don't question the professionalism or experience of the pilots involved.