It's much better to prepare the sauce seperately (vinegar, water, sugar). Pour the sauce into the baking tin, pour the flour mixture over. It'll infuse the entire pudding, but will leave the bottom deliciously moist and soaked in sauce.
Why do all chefs break eggs right into the mixture? What if one egg is bit off? I was taught in home economics to break it into a cup one at a time before adding it to the mix just in case of a bad egg... Just asking...