The problem there is the slide show. Converting a series of slides to a page in traditional vertical scrolling format works just fine. Overriding the back button behavior is just expecting a second wrong to make a right.

(Ironically, these days I'm relieved when I see a presentation is posted as a PDF: https://people.apache.org/~xli/presentations/history_Intel_C.... I'd much rather load a PDF than deal with all the shitty and insane ways people have figured out how to show presentations in HTML. Cough SlideShare: https://www.slideshare.net/garyachy/dpdk-44585840)