To me, this tiedown is not being used as a crutch.
I believe a tiedown is a tool, for finished horses going in events like polo, barrels, roping, other speed events for the balance added. My friend has a horse who is a wonderful example. He has NO training holes, and she rides him in a tiedown for barrels when speed is added. You can see him reach for it and stretch his head out where it's comfortable for him.
On the other hand my mare would probably kill herself in a tiedown, nor would she ever need one because she is extremely balanced naturally at high speeds.
Just all in how it's used, as well as preference to the horse. Used incorrectly it is incredibly dangerous and not useful at all.
Pssh.I didn't pick up the wrong lead
It's called a counter canter...
...A very advanced maneuver.