Is still in the the deleted items folder?

It is not possible restore a single record from a backup. I would try the following.

Note: You have to be careful you don't miss a step and end up overwriting
good data.

You have old-backup-file.
Create a new current-backup-file.
Restore the old-backup file.
Your BCM database is now in the state it was the day you made old-
backup-file.
Select the contact in question, and export it to a BCM file.
Restore current-backup-file.
Your BCM database is now back in the current "today" state.
Import the BCM file with the contact in question.
Your database should now have the deleted-by-mistake record.