Click tracking links are tied only to the specific contact that the email was intended for and sent to. If a person who receives a forwarded email clicks on a link, it will register as a click by the original recipient.
HubSpot uses identity tracking to associate a form submission from an email click with the original recipient of the email. If the recipient of a forwarded email clicks a link in the email and fills out a form, HubSpot will deduplicate using identity tracking and the form submission data will be associated with the contact record of the original recipient. To avoid overwriting the original recipient's data, use the social sharing module to allow contacts to share the web version of your email.