The author makes an assumption that the cause of the bad scroll was the ad at the top of the page. I have seen many pages on mobile and tablet that have broken scrolling like this, and many have nothing to do with ads. I have also seen reflow and scroll problems related to how custom web fonts are loaded, or to social sharing widgets.
It's also possible (and quite likely) the the faulty ad wouldn't cause exactly the same problems on other websites, due to the way in which it'll interact with the page, the size of the viewport of the browser, etc.etc.
That's true, but the video and related article doesn't confirm this. All we know is that the guy couldn't scroll down on the page. There's no indication right now that the ad is actually at fault.
We do know for certain that the ad is at fault. We can see that the ad is what is flickering into blocking the text. We also know that the NYT doesn't have a flickering block on every page.
For what it's worth, I've had this same issue on NYT site. I also assumed it was an ad causing the problem because refreshing the page to allow a different ad to load fixed it. (I don't block ads on NYT.)
You make an assumption that the author didn't confirm that the cause of the bad scroll was the ad at the top of the page. It's not extremely difficult to discover what piece of script is scrolljacking; frequently all you have to do is Ctrl+F for scroll events.
