teach mikami to be more careful with the notebook? or any of his tricks of carrying peices of the notebook, in his wallet/watch. he is so meticulous he should have sent him instructions thru a message through takada, or someone planned ahead for someone to temporarily take his place be capable at it.

wasn't near suspicious of the connection, so light couldnt contact with mikami?

D'oh!

He didn't do this because it wasn't the authours intention for him to do so.
Simple thing to remember. Will save you time asking things like this in the future.