Therefore, I need to put the following in .htaccess:

RewriteEngine On
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?mycompetitor\.com/
[NC]
RewriteRule .*\.(jpe?g¦gif¦bmp¦png)$ /images/nohotlink.jpe [L]

My question is will search engines especially Google consider this as a one way link from my website to my competitor, thus increasing the chance of his website being crawled and earn some ranking?