I´m not sure I got the question right, but the greater force production observed during eccentric contractions can be explained, at least partially, due to added forces. The force added by passive structures och the muscle fiber, such as desmin, probably makes up for the higher force production during this type of muscle work. As you´ve mentioned above, one of the conseqences of this are ruptured Z-lines. When it comes to explaining DOMS though, things get more difficult. See below.