I check the spam once in a while, but get too many to go through it every day. My blog gets from 1,500 to 3,000 hits per day, and that means more spam too. So it is feasable that a person leaves a comment with too many links in it at my site, it goes into spam and because I don't retrieve it, it's automatically deleted by the system and so askimet thinks it is spam.
It's always a good idea to be familiar with a blog to know if links are allowed before posting more than one. While there are people who allow none, most allow at least one or two before it's nabbed. I allow three.