Yes, it is possible to customize the emails that DocuSign sends in response to the "Envelope Declined" event, such that the email that the Sender receives is different than the email that the Signer (Recipient) receives. You can achieve this by customizing the Email Resource File (as described in this guide: https://10226ec94e53f4ca538f-0035e62ac0d194a46695a3b225d72cc8.ssl.cf2.rackcdn.com/docusign-system-default-email-formats.pdf).
Customizing the Recipient's "Envelope Declined" email is described on page 30 of the guide, customizing the Sender's "Envelope Declined" email is described on page 94 of the guide.
(Keep in mind that an Email Resource File is associated with a "Brand" -- so any changes you apply to an Email Resource File will apply to all Envelopes sent using the corresponding Brand.)