The concept of anchor text manipulation deals with replacing the URL with text which is more targeted to the keyword for which the site is trying to rank. Editorial links mostly do not use ideal anchor text. Many simply use the site link while others use text that is not ideal for SEO.
When the site owner or a SEO builds links to their own site, one of the many signals that point towards manipulation is when the anchor text is perfect. Try this...check OSE for Google.com. Look at the anchor text. Filter out the image alt text and just focus on the anchor text. Of course you will see "Google" a lot but you will see a nice variation of terms used to link to the same page. That is because those links are natural.
Look at your client's site. When you look at the top 20 links and 17 of them show "Best watch" for the anchor text, that is a clear sign of manipulation. Either the site owner or someone working on their behalf likely created those links. Another possibility is the site owner influenced the creation of those links. These links are not natural, or at the very least are less natural.
I hope that answers your question. I will also add the suggestion you are focusing on the wrong area. The best way for a site owner to build links is....to create amazing content which others find useful / helpful / amazing then let the world know about it. If you wish to build more links, then embed yourself as a member of the community related to the site's niche and sparingly mention the site.