piatkow - 2:46 pm on Nov 30, 2011 (gmt 0)
In fact you are taking down a url if it's an orphan.
I have seen pages stay in the SERPS despite all links being removed. They were only found with some very obscure long tail searches but they were still indexed.
Back to the OP, removing internal links does not guarantee that all links are removed. Somebody may have deep linked to the site.