Hey dexen, I'm the author of the post, yes I've reported the issue before to the internal team in charge of the blogging platform. I'll report it again. I've also been lobbying to move our technical blog to a different technology (I'd love a statically generated solution). Hopefully soon(tm).
Since migrating to a new platform might be considerable work you could suggest they install this plugin to disable the em-dash miss-feature: http://wordpress.org/plugins/disabler/
I believe wrapping the text in <code> tags might be a workaround, though I haven't tested it.
Re:What's New In Git 1.8.5
by contingencies on Wednesday December 04, 2013 @03:28PM
(#6849916)
–=--
Can't help but notice OP's blog platform replaces "--" (dash-dash) with "–" (U+2013, en dash), even in <span>s meant for code highlight. This prevents straightforward copy-paste of arguments like "--prune" to console ;-)