1.4x + 100-400L iS + 7D = autofocus!

When I use 100-400L IS and 1.4X converter on 7D I have to manually focus when using viewfinder - no problem with that, that's the way it is.
Using live view to do a moon shot, I noticed to my surprise that the lens autofocussed. I'm happy with that, but was wondering can anyone explain how that happens - I hadn't seen any reference to this feature before.
Would appreciate comments.

Live view uses a different AF algorithm than the AF sensors that kick in when the mirror is down. Also, using a non-reporting 1.4 TC on the 100-400L in bright contrasty situations, you should see the 7D AF work properly. The moon is such a target.

I use AF (phase) in my Sigma 150-500 and Kenko 1.4x tele. It works if I tape the pins

TeamSpeed wrote in post #10617089
Live view uses a different AF algorithm than the AF sensors that kick in when the mirror is down. Also, using a non-reporting 1.4 TC on the 100-400L in bright contrasty situations, you should see the 7D AF work properly. The moon is such a target.

Thanks for that explanation Teamspeed. It's a bonus feature really, although I don't recall any mention of it in anywhere else.