SymmetricBinding client can invoke the AsymmetricBinding service policy

In sample03, service is used the AsymmetricBinding and also client side is used the same.

But I changed the client policy to SymmetricBinding (while keeping same Encryption and Signature Parts) and invoke the service.

It was responding well .

Is it a issue, isn't it? Because AsymmetricBinding service can be invoked by a SymmetricBinding client policy (who has not a certificate).