Pointing to a federal court filing last month, the Ecuadorian plaintiffs suing Chevron Corp. contend the oil giant is withdrawing its claim that an $18 billion-plus judgment against it was the result of “sham” and “objectively baseless” litigation. The Ecuadorians, referencing a Jan. 4 procedural filing …, this week called the move a “significant tactical retreat”…The plaintiffs contend the move also is, in effect, conceding that there is evidence that the company caused pollution in the country…Chevron spokesman Kent Robertson said in an email…that the company — which has consistently denied the merits of the Ecuadorians’ environmental allegations and continues to do so — has “not withdrawn anything, let alone a claim,” in its racketeering action.