A federal judge has declined to toss a lawyer off a civil case for talking to a former employee of his client’s adversary.In a written opinion this week, U.S. District Judge Elaine Bucklo denied a motion to disqualify Michael P. Padden of Pearne & Gordon LLP from representing Freeman Equipment Inc. in a patent-infringement lawsuit against Caterpillar Inc.Bucklo rejected the argument that Padden violated ethics rules by speaking to William Perry.Perry is a retired Caterpillar employee who worked for nearly 30 …