Abstract We analyse a curious conceptual implication of a gamma angular correlation experiment using the 28Si+ 12C orbiting reaction performed by Ray et al. [Phys. Rev. Lett. 57 (1986) 815]. Here “which path” information of the gamma emitted from 12C can be obtained without affecting the interference pattern of the pulses. This is possible because the interference originates from a quantum mechanical superposition of 12C nuclear angular momentum eigenfunctions and the coherence among these interfering nuclear angular momentum wavefunctions is independent of the accuracy with which the point of origin and the direction of the gamma pulses are determined in the configuration space.