For what it is worth, scuttlebutt is that Carryspeed was sued by BlackRapid, and the lawsuit was dragged out enough that Carryspeed gave up. Not sure how they viewed the product as a knock off.
Black Rapid has a patent on the sliding camera strap.
CarrySpeed LumaLoop and others have left the field or discontinued products as result of the patent grant. Carryspeed was sued by BR and seems to have gone out of business.
Millionway International, Inc. ("Millionway") and Black Rapid are competitors in the camera strap market. ( Millionway Int'l, Inc. v. Black Rapid, Inc., 4:13-CV-01780, Dkt. 1). XP Photo sells Millionway's products. Dkt. 1 ¶ 17 (Original Complaint). On November 1, 2011, the United States Patent and Trademark Office ("Patent Office") granted Black Rapid a utility patent on a camera transport system and method, known as the 729 Patent. Dkt. 1 ¶ 10. The Patent Office issued a reexamination certificate confirming the validity of the 729 Patent on March 5, 2013. Id. On March 6, 2013, Black Rapid filed suit against Millionway in the United States District Court for the Central District of California ("California Court") for infringement of the 729 Patent. Id. ¶ 12. Millionway did not answer, and Black Rapid filed a motion for default judgment on April 5, 2013. Dkt. 7, Ex. F. The California Court entered default judgment against Millionway on June 10, 2013, and additionally permanently enjoined Millionway and its agents from infringing the 729 Patent. Dkt. 7, Ex. B (granting Black Rapid's motion for default judgment). Therefore, the California Court deemed Black Rapid's factual allegations in its original complaint as true, including a determination that Millionway's camera straps including the "Carry Speed" line of products, infringed the 729 Patent. Id.