O.k to actually further elaborate on what is going on there.
6d~ad - the very first frame of shield cancels into throw NO MATTER WHAT as long as the throw input comes out on the next frame. This is presumably because of input leniancy in button combinations, and 5a works the same way, 6a~ad cancels will cancel the startup of 5a into a throw. You could also do this with 4d~ad
So basically you're kara canceling shield into throw.
This is what lets H-Moon and F-Moon do shields into throws.
You can test this yourself and visually see that the first frame of a shield will come out before your throw.
You can also do this off low shield with either 1 2 or 3 into 6 or 4 ad but this is slightly harder to do a low shield into the throw.
What this actually means in application - on wakeup doing this os you can actually reversal this and it will shield then throw against meaties, and if they are not attacking you, you will just throw them.
This loses to mistimed meaties or just being out of range of the throw, or just wrong shielding.
Note that this particular "feature" seems to include other macros such as dashing or dodging, but for practical application it doesn't seem as usable.
EDIT: I got blown up by adviceowl's edit.
Other stuff: Kara throws are actually legit. Im seraching for somem oves that get good benefit from it though. So far Fryougi 5c seems the best and increases her throw range significantly.