Thanks for the responses guys. I can access it on the driver's side as well, and for the 3 gear seems to be pretty easy to access. I was more concerned as to whether or not it can actually loosen or tighten depending on side, but I haven't thought of a way yet where the diff can tighten or loosen under normal driving conditions.
I would imagine it is possible if you REALLY REALLY diff out the car. I.e., are high centered, but one wheel is touching the ground... and you go full throttle. In that case, the center diff gear and one outdrive spin at really high speed while the other sits still... you could generate enough friction on the thrust assembly to actually move the bolt inside the lock nut. Would still take quite the scenario to pull off. I myself, am always very careful to keep my diffs in great shape, and if I ever do high center, im careful pulling the trigger.
I am actually running my diff backwards right now, on accident. Forgot to pay attention to it's orientation last rebuild... zero issues two full track days later.