Right, then there must be something wrong in the way the DEPTH_COMPONENT texture is interpreted thereafter when it’s used for the 2nd pass, the shadowing one, because the exact moiree pattern that’s seen in the picture resurfaces as z-fighting!
Are you talking about the artifacs on the back of the bear? This is a known artifact in conjuction with shadow mapping, I think it is called “shadow acne” and is usually fixed by biasing the shadowmap depth values by a certain amount.
See pg. 36 here (Shadow Mapping - Isidoro, GDC06), and for a better example of this shadow acne, see pg 6. here (Shadow Mapping, King, GPU Jackpot '04).