A reasonable modification of an established phenomenological model is developed to investigate the recent report on sign reversal of magnetoresistance (MR) in 99.95% La0.7Sr0.3MnO3(LSMO)−0.05% paraffin wax hybrid nanocomposite system. At zero external magnetic field (H), all the grain boundary (GB) domain walls (DWs) are assumed to remain pinned at the pinning well. Due to depinning of spin‐polarized DWs with H, a negative MR response is observed between 15 K and 300 K. The GB DWs, which are expected to be pinned with strong pinning strength at and below 10 K, have undergone spin‐flip tunneling, thereby increasing the resistance of the composite with H, i.e., positive MR. The strong pinning phenomenon associated with positive MR is analytically modeled using a skewed Gaussian distribution of pinning strength at and below 10 K.