Good catch. We agree that should open in a new window when it's set to go to the user's FB profile.
To update now, edit the /modules/mod_sclogin/helper.php file. Around line 156, you'll see the getSocialAvatarImage function and at line 169, you'll see:
$html = '<a href="' . $profileURL . '">' . $html . '</a>';
Update that to the below adding the target parameter:
$html = '<a target="_BLANK" href="' . $profileURL . '">' . $html . '</a>';
Hope that helps!
Alex