XPath选择器在chrome dev工具上工作，但没有php domXpath，为什么呢

Trying to scrape a page using xpath and php domxpath, the xpath expression is pulling data in chrome dev tool, but it returns empty result on php code, Here is the sample page

    $dom = new DOMDocument();
    @$dom->loadHTMLFile($file);
    $xpath = new DOMXPath($dom);    

    $nodes = $xpath->query('//*[@id="detail_bullets_id"]/table/tbody/tr/td/div/ul/li');

I tried saving entire file as html file and did xpath query on that. Can someone help ? Thanks.