I don't think so. There's been ample notifications way before aug1 for coinbase users that if they want bcc, transfer their bitcoins to other wallets that supports bcc. Coinbase isn't the only exchange wallet and users were given options. If they don't want to support bcc, then won't
Absolutely,if coin base had not given notification,then legal actions could be taken against coin base.But they had already announced that they would not support BCC and if their customers need BCC,then they would have to withdraw their bitcoins and store them in separate wallets to claim BCC.So nothing could be done.