I think it's a moot detail. Shouldn't affect SEO in the same sense that the trailing semi-colon doesn't affect CSS in the last attribute. Test it. Do a link search on Google for the link with the trailing slash, and then without. If Google is giving you the same number of results, in the same exact order, it's not affecting your SEO.
I do understand the devil is in the details, but some of the very very small "SEO" concerns are really not worth being concerned about unless you have all the amazing content in the world that you or anyone could possibly handle.