1) Common sense: You send a racquet to a reviewer; you should expect a review. Why else would you send a racquet to a reviewer? If you don't want them to review it just yet or post a review, say it in clear language.
2) Owner got angry at Beckett for posting his thoughts on TTW, it wasn't even a video review. The thoughts weren't all bad; in fact, Beckett said some good things about the racquet and said that he liked their strings.
3) Owner implied Beckett jumped the gun and was therefore unprofessional. Note that another forum member also posted his thoughts about the racquet's performance on the SAME THREAD before Beckett did, the only difference being that he reviewed it very positively. I wonder if the owner contacted him too and demanded the racquet to be returned; somehow I doubt it. So I guess it's ok to review it prematurely, as long as you only say good things about the product
4) Owner had plenty of time between the occurrence of the unnecessary drama and when Beckett posted his video to reconcile and clear up any misunderstandings. Apparently, he felt it wasn't necessary. At the same time, folks on the forum were giving ND the benefit of the doubt and questioning the veracity of Tenncom's recounting of events. Beckett's fully justified in posting his video in order to uphold his and his channel's reputation.
5) Let's say the owner of ND was having a particularly bad day and was under duress near the launch of his product. If you're a new company, you should be EVEN MORE careful about how you treat reviewers than the larger manufacturers. To get so worked up over somebody's genuine opinions on his product that his company worked so hard to launch is rather unwise from a business standpoint. Again, if he regretted his actions following the email correspondence with Beckett, he had plenty of time to reach out and reconcile; he didn't, which indicates to me that the way he acted is a reflection of who he actually is.