Bob, in your article you state: "In live view most DSLRs keep the mirror up all the time so mirror induced vibration isn't an issue. However it's still necessary to either use a self timer of a remote release so that you don't induce vibration by touching the camera."
I just tested my T3i, and in live view when I take the picture the mirror clearly flips down and back up. I am not sure *why*, but I can clearly see the through the viewfinder for a moment while the picture is being taken in live view.
My 7D doesn't. Try setting the AF mode in Live View to "Live mode" rather than "Quick mode". In quick mode it drops the mirror down to AF. Not sure what it does in quick mode if the lens is set to MF. Can't say for sure if the T3i is the same as the 7D because I don't have a T3i around to test.