The thing is, no particle is defined when it interacts. At our present level of understanding the only defined particles are the individual green's functions that appear in perturbation expansions, the lines in Feynman diagrams.
We see interacting particles in detectors, but since nobody can write down what field configuration they mean by "a photon," I can defend my phrasing - but you can defend yours too because I know what a bird is even if I don't know how they work.
We see interacting particles in detectors, but since nobody can write down what field configuration they mean by "a photon," I can defend my phrasing - but you can defend yours too because I know what a bird is even if I don't know how they work.