Does Quantum Mechanics Disprove the Principle of the Identity of Indiscernibles?

Alberto Cortes, in [1], attempts to show (a) that Leibniz's Principle of The Identity of Indiscernibles (L) is a principle restricted to individuals (as distinct from a class of entities Cortes takes to be non-individuals),' and (b) that photons (light quanta) appear to violate L (since they don't obey Pauli's Exclusion Principle). L is stated by Leibniz as "no two substances are completely similar, or differ solo numero." In second-order quantification theory with identity L becomes: