TheMadScientist - 9:28 pm on Mar 29, 2010 (gmt 0)
http://www.example.com/directory/ is the same content as http://www.example.com/directory is there a duplicate content issue on Yahoo SERP?
So, that SEO firm was probably doing that for a reason.
Yes, absolutely it would be duplicate content, and you're probably right about the reason they are not serving any content, but IMO it's better to redirect than serve a 404, because then you not only tell bots where the information is, you also direct any visitors who try to visit with the / to the correct location, and you get credit for any links to the incorrect location...
Personally, I think the SEOs working on the site could probably make an adjustment and do a better job than they currently are, if they are not redirecting... I certainly would (and do) redirect for the reasons I have mentioned.