Mired in a $27 billion environmental lawsuit in Ecuador, Chevron Corp. has taken the unusual step of trying to subpoena the other side's lead lawyer, arguing that he has committed fraud upon the court…The move is the latest bare-knuckled legal tactic…Chevron has pursued…Since February, the oil company has been filing motions in courts throughout the United States, seeking to depose consultants who worked for…the plaintiffs' legal team. Chevron even won access to hours of unused footage from a documentary film about the lawsuit. In each instance, Chevron is searching for evidence of improper conduct by the opposing lawyers, evidence the company hopes will show that the trial has been tainted…Ilann Maazel, [a] lawyer on the plaintiffs' team, called the spate of subpoenas a last-ditch attempt to undermine the trial before the judge reaches a verdict, possibly next year. [also refers to Texaco, Petroecuador]