The end of the article seems to say that since people copied the feature between when it was first invented (by Loren B.) and when the patent application was fi

The end of the article seems to say that since people copied the feature between when it was first invented (by Loren B.) and when the patent application was filed, that counts as prior art. IANAL, but isn’t that false, if the period between the invention & patent application is short enough? What is it, a year or two? Edit: Gojomo says elsewhere in this discussion that the grace period between public disclosure & the latest you can file is one year.