it's pretty clear from the article
1. MIB features the Hamilton ventura watches.
2. the president of Stührling appeared on a TV show - ShopNBC, which is a home shopping network, in which the host mentioned that a movie is using a similar watch.
3. but of cos the public, at first glance, while watching the MIB movie will not know its a Hamilton, and those who were watching ShopNBC will assume it's a Stührling in the movie.
4. so in order for the public / fans of MIB to not be confused, and thereby possibly purchasing Stührling watches instead of Hamilton...Swatch decides to sue them so they will be forced to cease production of the watch.