SEO By Yoast Plugin Problems

I was working on this page, http://www.smartcellsusa.com/fall-protection/ and the SEO checker by Yoast Plugin we have claims that there is only 1 word in the body text and that the keyword “fall protection) is not used at all in the content of the page.

How can I change this? Clearly the keyword is used in the content. Is this a problem with the plugin or perhaps its due to the template of the page? Do you know why it does this? Thank you.

I’d also like to add that the SEO Checker tool works for pages published in our blog/press release area. Which can be found here http://www.smartcellsusa.com/category/blog/