Nothing wrong with GitHub and it's fine to distribute binaries, most people would follow the link and figure out "raw" on the meta-page is what's needed for actual binary download - the mistake was in Dave assuming the link lead directly to the file rather than the meta-page.
Most software people (for which GitHub is meant for) will have seen this behavior before in revision system web front-ends (Jira, ViewVC etc. works the same way) which really does revolve around meta-data rather than binary data. File-specific services like Dropbox, SharePoint etc. are usually the other way around, binary download before meta-data - probably the culprit here.
As it will remain impossible to link to both a raw and the meta, through one single anchor on the name of a file, this duality will remain to exist in the HTTP hypersystem. One usability fix may be to do as some (the Archiva maven repository front-end comes to mind) and show a popup on mouse-over, to let the user see there are more than one option. Ideally though, we add a header to the HTTP protocol which browsers will set when issuing a GET to download a link (i.e. right-clicking and using "Save link as...", so that browser and server has a way of signaling the users intention. The server could then specifically redirect to the binary file or the browser could catch the mime and say "This is a HTML5 file, are you sure you wish to save rather than view?".