If you were to send BTC accidentally to a BCC address then would the funds have been sent to the same private key on the BTC blockchain? Would the owner of the BCC key be able to retrieve those coins in a BTC wallet?
To answer your question, if the person whom you are sending the BTC/BCC have the private key of the wallet, then he can access the BTC as well as the BCC in the wallet.
Both are just different chains, but each wallet share the same private key in both network.
For more detailed answer about sending BTC to a BCC wallet, click here