If you want to better understand the CRISPR patent dispute, this article lays out the arguments very clearly.
https://www.statnews.com/2016/03/18/crispr-patent-dispute/
(For those of you who aren't in on the joke, "The Heroes of CRISPR" was written by the director of the Broad Institute, which incidentally has Feng Zheng on its payroll. For that reason Eric Lander has been roundly criticized for attempting to weigh in on the history early. My friends who work in and around Kendall Square say that some of the criticism is overblown, the article points out a lot of people who didn't get much recognition prior, but still... it's a bit skeevy so you might want to take the latter half of the article with a grain of salt as it's not necessarily factually wrong, but the emphasis might be distorted and there is a risk of omissions.)
In the case where this was a known technique that had significant difficulties in translating to eukaryotic work, then the Broad Institute's work would be significant. That was not, however, the case. Very little needed to change, and the technique has been widely applicable.
Just a quick look though Doudna's publications shows that this is an issue with a great deal of background work behind it, years of effort that fortuitously resulted in an incredible invention. Then, someone comes along, copies your work in some different bugs, and claims ownership. It's really no more complicated than that.