The one good question posed by this article is about whether Marty and Jennifer would exist in 2015, after they have just gone off in the time machine w/ Doc Brown in 1985. At that point, we might think they should be removed from any future time line until they return safely to 1985. I can only surmise that when traveling to the future, the Delorean travels along the future time line it is leaving, without regard for any changes it may introduce by doing so.
The author fails to realize one key point, the fact that Marty and Jennifer returned afterwards. If Doc had wanted a more dramatic experiment, he would have sent Einstein back in time after the first time transition. It would have been the same as BTTF2, only with a dog and spanning a minute, instead of our heroes and 30 years.
It would also have been one hell of a shocker for Marty and Doc to see Einstein appear before it even leaves with the clocks marking two minutes more than it should.
