he was walking and talking with his lieutenant Rangiku when they had turned a corner to see Hinamori stab you with her zanpakuto, her reasons had something to do with Aizen. Toshiro and Rangiku saw that whole thing

Toshiro: his eyes widen Hinamori!

Rangiku: she covers her mouth in disbelief, eyes wide

Hinamori immediately ran away, vanishing from sight