Abstract
It is shown that fixed poles in photoproduction amplitudes emerge from the equal-time commutators in a natural way, the latter ones being the consequence of an assumed sharply retarded commutator in the reduction formula. We discuss in detail, how the residues of these fixed poles which under the smoothness assumption are proportional to a strong form factor can be modified and cancelled. Such a cancellation seems to be rather artificial and necessitates the existence of a Kronecker delta in the retarded commutator of the pion current and the electromagnetic current. The fixed poles due to the equal-time commutators discussed occur only in negative-parity helicity amplitudes and hence are evasive.
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