There are a few explanations that work:
The first possibility: this sort of thing is an exercise in counting the hits and ignoring the misses. If a passage can be interpreted so that it kinda agrees with what we know from science, then this is counted as "proof" of the Qur'an. If some other passage doesn't work with modern science (the verse about the sun coming to rest in a muddy swamp, for example), it's disregarded as poetry or metaphor. My money's on this one, personally.
The second possibility: if we go with what you suggest and the conclusions that this web site drawn are actually correct about the Qur'an verses it mentions, it only gets you to a supernatural origin, not necessarily God. Couldn't the Devil have been capable of dictating a book to a 5th-Century person and inserting modern scientific facts into it? Maybe the Qur'an's just an attempt by some demon or evil God to turn people away from the real religion. Maybe Norse mythology is right and all "miracles" in other religions are just elaborate trickery by Loki. Can you disprove this possibility? If we believe Norse mythology, Loki's very powerful and very devious, so he'd be more than capable of pulling off something like this.