Nucleon knockout experiments using beryllium or carbon targets reveal a strong dependence of the quenching factors, i.e., the ratio ( R s ) of theoretical to the experimental spectroscopic factors ( C 2 S ), on the proton-neutron asymmetry in the nucleus under study. However, this dependence is greatly reduced when a hydrogen target is used. To understand this phenomenon, exclusive 1 H ( 17 Ne , 2 p 16 F ) and inclusive 12 C ( 17 Ne , 2 p 16 F ) X , 12 C ( 17 Ne , 16 F ) X as well as 1 H ( 17 Ne , 16 F ) X (X-denotes undetected reaction products) reactions with 16 F in the ground and excited states were analysed. The longitudinal momentum distribution of 16 F and the correlations between the detached protons were studied. In the case of the carbon target, there is a significant deviation from the predictions of the eikonal model. The eikonal approximation was used to extract spectroscopic factor values C 2 S . The experimental C 2 S value obtained with C target is markedly lower than that for H target. This is interpreted as rescattering due to simultaneous nucleon knockout from both reaction partners, 17 Ne and 12 C .