Q: Dear Ethics Lawyer, Our firm defended client X in a product liability suit in which other companies in the same industry were also defendants. The various defendants, including our client, entered into a written joint defense agreement and collaborated as a group on strategy, briefing and arguments in the matter. During discovery initiated by the plaintiff, we learned that our co-defendant Y had hired one of X’s engineers who had delivered to Y confidential and proprietary product designs of X, which Y had then used to improve its product. The product liability case has been settled, and now X would like our firm to pursue an action against Y and the former engineer for misappropriation of trade secrets and other claims relating to Y’s use of X’s intellectual property. We sent a demand letter to Y and its counsel responded, alleging that we have a conflict of interest because of our participation in the joint defense agreement with Y, and the relationship of product design at issue there to the similar issue that would be at issue in the new matter. Is this a problem for us?