Yesterday I was reading an article and, part way through, a video started playing on the sidebar. I saw it, thought it looked interesting, but wanted to finish

Yesterday I was reading an article and, part way through, a video started playing on the sidebar. I saw it, thought it looked interesting, but wanted to finish the article before watching. I paused the video. As I scrolled further the video resumed (reproducibly). By the time I'd finished the article it was auto-playing a new video, and there was no way to find the original.