To me the issue goes the other way. The idea of “losing deontological protection” suggests I’m allowed to ignore deontological rules when interacting with someone. But that seems obviously crazy to me. For instance I think there’s a deontological injunction against lying, but just because someone lies doesn’t now mean I’m allowed to kill them. It doesn’t even mean I’m allowed to lie to them. I think lying to them would still be about as wrong as it was before, not a free action I can take whenever I feel like it.
To me the issue goes the other way. The idea of “losing deontological protection” suggests I’m allowed to ignore deontological rules when interacting with someone. But that seems obviously crazy to me. For instance I think there’s a deontological injunction against lying, but just because someone lies doesn’t now mean I’m allowed to kill them. It doesn’t even mean I’m allowed to lie to them. I think lying to them would still be about as wrong as it was before, not a free action I can take whenever I feel like it.