@Twinmoon222 wrote:
I’m wondering when he decided to delete the file, did he get notified that if he deletes it that it will delete from my account too?
If the file was shared with you via a shared link, then you didn't have the file in your own account (unless you specifically saved it to your Dropbox). If you were just clicking the link to view the file, you were viewing it in his account.
If he deleted the link, he would have received a message that says "The link will no longer work for anyone who has it." If he just deleted the file directly, he wouldn't have received a message about others accessing it.