  We investigate the size of potential higher pseudoscalar resonance
contaminations of the estimates of isospin-conserving and isospin-violating
$\pi NN$ couplings obtained using the 3-point function method in QCD sum rules.
For the isospin-conserving case it is shown that conventional models of the
isovector pseudoscalar spectral function imply resonance decay constants large
enough to create significant contaminations, and that assuming these models are
incorrect, and that the decay constants are actually much smaller, implies
physically implausible values for the flavor-breaking quark condensate ratios.
For the isospin-violating case it is shown explicitly that such resonance
contamination is unavoidably present and precludes using the 3-point function
method as a means of estimating the at present unmeasured isospin-violating
$\pi NN$ couplings.
