The reviews are coming by some client side script so in response string you are getting some un-compiled Jquery-js content.
the below jquery function is fetching the reviews
$BV.ui("rr", "show_reviews", {
productId: " 6457603",
contentContainerDiv: "BVReviewsContainer",
summaryContainerDiv: "BVCustomerRatings",
secondarySummaryContainerDiv: "BVSecondaryCustomerRatings",
mediaGalleryContainerDiv: "BVMediaGalleryContainer",
sort: "helpfulness",
dir: "desc"
});
So you are not able to see the review comments.
Hope this helps !!!
Regards,
Reishabh