In Chomsky (2000,2001), the passive, along with unaccusative and other forms of participle object constructions, with the light v is considered 'defective' because as Chomsky (2001:6) says: light v of a passives lacks: 1. The ability to assign Accusative Case; 2. This inability results from not having a phi-complete bundles, in fact only [person] is valued after the light v probes. That's why the DP object in passive sentences has to move for Nominative Case assigning in T and complete the phi-agreement features there.
What remains mysterious for me is not this movement for Nom Case, neither the defective nature, but I have data in which both a Transitive Active v has the same phi-features exhibited on this 'defective' light v of the passive. Those who are familiar with Phase Theory in the minimalist program, please help me understand more this 'defectiveness notion' in the light of passives.