DownSideUp,
A pushrod is (usually) a balsa rod, 3/8" square to 1/2" square balsa on that size of plane. It has a short , 2" to 4", piece of wire on each end with a clevis threaded on for connecting to the servo at one end and the rudder horn at the other end.
Sometimes on ARF they use a piece of 3/8 dowel rod for convenience, and that is heavier than balsa.
If you can imagine, when you pull 5 'g' in a loop or turn the pushrod weighs 5 times as much. Try sticking you fingers or a stick inside the model and push down on the middle of the pushrod. Does the rudder move? If it moves to the left that could be the cause of the left flick out of high 'g' manoeuvres.

I always use a closed loop on rudder. I put a control horn on each side of the rudder, back to back symmetrical. To each I attach a piece of light steel wire coated with nylon (fishing shops sell it as 'trace' wire, and many hobby suppliers sell it as well now). Hobby shops sell the connectors, often with some wire.
Both wires are led into the fuselage (often crossing over) and they go to either side of the rudder servo arm. So left rudder command pulls one wire and right rudder command pulls the other. It is also called a pull-pull system.
You adjust the wires firm, but not tight, and it is very positive, light, and cannot be affected by pulling 'g'.
Does that help?
Alasdair