Easily. When it gives you a merge conflict, you just commit the file generated from the merge without dealing with the conflicts - or you do try and deal with the conflicts but you miss one. That sort of thing is caught very easily with code, because it's not going to compile with all of those>>>>>>>>>> and <<<<<<< in the file. ddoc, on the other hand, can legally contain>>>>>>> and <<<<<<<, so the documentation compiled just fine. No one caught it, and it ended up in the master repository.
I know, but usually git is keeping track of a merge and won't let a file with merge markup be committed unless you specifically force it. If you go through the normal merge conflict resolution process all of that should be removed. Anyway, it doesn't look like the markup got committed, I think it was just generated from a file that hadn't been resolved yet.
