Thanks for your response Nat. I figured out the issue.
We have two version of the site in question, win auth and forms auth. After some digging around a little bit I found out that one of the user controls was breaking in the win auth version - hence the page as well. It was working fine in forms auth. I forgot to add an appsettings entry in the win auth's web.config. So I am guessing when the crawler went to the page, saw the page was broken - it didnt crawl it and recorded the warning message in the crawl log.
After fixing the user control, the page was crawled as expected.