He was referencing a book that made that case if you "squint". If you read that as actually a serious "this caused world war 1" statement rather than. This looks to have gotten some dominoes rolling that may have contributed to WW1 then that says more about you than it does about the article itself.
Re: "This looks to have gotten some dominoes rolling that may have contributed to WW1 " - people who believe this should read some history about beginning of WW1. I recommend starting with "The Guns of August".