The grinding legal struggle between Fox and Dish Network over the satcaster’s ad-skipping AutoHop and Primetime Anywhere features just became a heightened war of words. “Dish’s colorful allusions, over-the-top mockery, and baseless accusations that Fox is attempting to relitigate the 30-year-old Sony case have one purpose: to draw the Court’s attention away from the fact that Dish is directly infringing Fox’s copyrights and breaching its license agreement with Fox,” said Fox in a brief (read it here) filed Thursday. The reply by Fox earlier this week is in response to a brief Dish filed on January 17 with the Ninth Circuit. In that filing, Dish claimed that Fox’s appeal over the November denial of its request for a preliminary injunction against the features was just a recycling of the old Betamax court battles of the Eighties. Dish also argued that, like the Supreme Court’s 1984 decision in Sony Corp. of America v. University City Studios Inc., its AutoHop features is protected by fair use and limiting it would effectively render any use of DVRs illegal. Fox, who filed its appeal on November 9, doesn’t see it like that. “Reversing the district court would not, as Dish threatens, imperil DVRs; it would simply restore the status quo,” says the brief.

Related: CBS Says Dish Concealed AutoHop In Retransmission Deal

Introduced last May, AutoHop allows Dish subscribers to leap past commercials in programs that have been recorded off network TV via the PrimeTime Anytime service the day before. CBS, NBC and Fox have all filed copyright infringement suits against Dish to get the service stopped. Fox Broadcasting, Twentieth Century Fox Film Corp. and Fox Television Holdings, Inc. are represented by Richard Stone, Andrew Thomas, Amy Gallegos and David Singer of LA firm Jenner & Block and Paul Smith from the firm’s NYC office. Annette Hurst, William Molinski, E. Joshua Rosenkranz, Peter Bicks, Elyse Echtman, and Lisa Simpson from San Francisco’s Orrick, Herrington & Sutcliffe represent Dish Network.

Deadline's Dominic Patten - tip him here.