Hi,

you didn't post the link that throws a 404 on your website.

The link: http://www.kooklekkerder.nl/101-voorgerechten/166-recept-pasteitjes-met-runderragout
looks already indexed by Google but this has nothing to do with JSitemap because it's not included in the sitemap or sh404sef that correctly generates the alternative version http://www.kooklekkerder.nl/recept-pasteitjes-met-runderragout.

If you want to remove the link http://www.kooklekkerder.nl/101-voorgerechten/166-recept-pasteitjes-met-runderragout from Google you need to disallow it in the robots.txt for example.

We have not the Dutch language for the component, but it can be translated because it uses the standard Joomla translations files.