Earlier quoted context omitted.
In Safari (iPadOS), I couldn’t get out of the site using the back button (unless I hit it fast enough to get past whatever it was doing to the browser history).
Interesting, it works fine on Firefox. I was able to reproduce it using Safari. After poking around I noticed it's a tumblr blog, so I tried some other tumblr blogs with the same result. It seems Tumblr's nav code does not get along with Safari/Webkit.
Thanks. That's good to know for the future, at least when I can easily identify something as a Tumblr blog. At least this wasn't one of the more egregious browser history hijacking situations. I've been on some sites that polluted the browser history as I scrolled through the page (each subheading coming into view got an entry). Two quick taps of the back button was enough to get around this one.