Quirrel is known to be good at dissociation. Harry’s (Demented) dark side hates everything that moves. Even if Harry’s dark side is not (part of) (the original) Voldemort, I wouldn’t be surprised if Quirrel can dip into a hate-everything personality for the time it takes to cast the Killing Curse.
(Of course, there is insufficient evidence either way.)
Quirrel is known to be good at dissociation. Harry’s (Demented) dark side hates everything that moves. Even if Harry’s dark side is not (part of) (the original) Voldemort, I wouldn’t be surprised if Quirrel can dip into a hate-everything personality for the time it takes to cast the Killing Curse.
(Of course, there is insufficient evidence either way.)