You'd expect an aussie to be practical!
Obviously, the A tuner has been replaced with another with higher pole. However, I fail to see why the string would work its way up to the top of the pole. I always make sure it works its way down! And, if there is a string angle problem, I use so much of the string to wind up, that the final wrap gets low enough. Also a practical solution, not recommended by string makers.
Swap the tuners, or get a new for the A. String retainers only adds fuzz, like harder to change strings, stepwise tuning due to friction, etc.