Did Tekton actually sue Erin, or merely "threaten" to sue? What would constitute a "threat"? If Erin relies heavily on measurements, an incorrect measurement would could damage the company's reputation and I can see why they would take action. If the Tekton representative's explanation is correct, that action involved getting Erin to redo the measurements and repost his review after such correction in the measurement protocol. While this certainly suggest pressure on Erin to change his review to avoid further threats, the ball is in Erin's court--he could still post a negative review, but, at least he will not have published factually incorrect measurements.
It appears to me that there is a bit too much hysteria about evil companies attacking reviewers. This does not happen often, and in this case, it is not even clear from the discourse here that Tekton did anything more than protect their interest by getting the reviewer to do the measurements correctly. It is pure speculation on the part of the posted video that the measurement issues were minor and insubstantial.