Actually, he jumped out of the window in his Shinigami form... and Karin said she could see him as a Shinigami already, so she should've noticed him changing...


I don't think they know of everyone that can pose a problem to them, I think Yuruichi is around also... I think I saw her reaction when they felt the spirit pressure...

So they must not know from either Ichigo, Isshin, Urahara, or Yoruichi...