I would guess that MC doesn't want seme to suspect that MC is suspicious (since saying "I smell blood?" could make him out to be a witness), or else he might killed in order to be silenced
also when he met him as a client "for the second time in the same day" he should've said your voice is familiar, did we meet before?
anddddf when he said I'm sorry I can't drink when he saw the killer's D covered in wine... the uke slipped too many times so i guess the killer already knows that he can see,
Im not blind so i dont know exactly but ... dont blind people have better hearing and smelling? Wouldnt a blind guy say "i smell blood. Did you get hurt?" after being pushed to the bloody corpse? I mean ... he even said he smells it so ... why ignore it?