There is a lot of misinformation going around about the lethal dose of nicotine. Many who are writing about e-liquid cite a long-known "fact" about how much nicotine is required to be lethal, but this information is based on a very old study done in the 19th century that is extremely flawed. The dose you state appears to be based on that study. New studies are showing the lethal dose is at least 4 times higher, although most authors who are trying to make vaping look bad will still cite the old, flawed study.
Also, as I and others stated earlier, this article is chock full of factual errors. I wouldn't believe anything that author says unless it's backed up with another, credible source. It would be awfully nice if writers of articles took the time to actually do background research on what they're writing, but unfortunately, that is not the world we live in...