Before revision:  Recently, Breiman et al. (2020) presented a hypothesis that could shed some light on i) and ii), specifically, it has been proposed that during the subject-to-subject transfer SARS-CoV-2 conserves on its capsid the erythrocytes' antigens of the source subject , causing a potential immune reaction in a receiving subject which has previously acquired specific antibodies to the source subject antigens.
After revision:  Recently, Breiman et al. (2020) presented a hypothesis that could shed some light on both aspects. Specifically, it has been proposed that during the subject-to-subject transfer SARS-CoV-2 conserves on its capsid the erythrocytes' antigens of the source subject , causing a potential immune reaction in a receiving subject which has previously acquired specific antibodies to the source subject antigens.