What you experienced was the effects of increased byproducts of fermentation due to the long period (3 days) of fermentation. Those byproducts of fermentation affect not only crust flavor but also the texture, color and aroma of the finished crust. The basic Lehmann dough formulation will usually make it out to three days without any difficulty, although the dough may become quite extensible (stretchy) at that point, especially if the hydration is on the high side, say, 63% or better. After about three days, the basic Lehmann dough is also prone to depletion of natural sugars. As a result, Tom Lehmann often recommends that some sugar be added to the original dough when the dough is intended to go beyond about three days. That way, the yeast will continue to be fed and there will be sufficient residual sugar in the dough to contribute to crust coloration but not so much as to cause the bottom of the crust to brown prematurely or excessively when baked on a stone surface, as in a deck oven or on a home pizza stone.
After about three days with a basic Lehmann dough, the gluten structure of the dough will start to degrade as a result of enzymes that attack and weaken the gluten structure. Often, water is released into the dough, making it damp and a bit slack. This latter condition can appear as soon as three days but it is usually a few days later under normal circumstances (in which you have followed the basic instructions for making the Lehmann dough). Trying to get a good crust at that point becomes problematic. The dough can be difficult to handle, thin spots and tears can occur during shaping and stretching, and the finished crust can be flat and lack color, and be almost cracker-like in texture. The crust flavors will be much enhanced, because of all the flavor-enhancing byproducts of fermentation, but at the expense of the other qualities that you want in the finished crust. Once the dough reaches this point, it is for all intents and purposes "dead" and cannot be resurrected.
What you might try sometime as a simple experiment is to make a basic Lehmann dough as you have been making it and let the dough ferment in the refrigerator for around 6 or 7 days. If your schedule permits, you should watch the changes in the dough over that time, in terms of its volume expansion and the way the dough expands. I use a glass storage container such as a 1-qt. Pyrex glass bowl to view the dough, and I also look at the bottom of the dough to see when bubbles start to form there. Then, after about 6-7 days, let the dough warm up on your kitchen counter for about an hour or so and try to form a skin out of it. The purpose of doing this is not to necessarily make a pizza out of the dough, which may or may not be possible, but to teach you to recognize the signs of a dough that is past its prime or at least headed in that direction. I have made and killed several doughs just to learn these lessons. But once you learn them, they will always be with you. If you decide to conduct an experiment along the above lines, I hope you will return to the forum and describe your results.