An Ecuadorean judge whose testimony threatens a $19 billion judgment against Chevron must not be credited because he was paid off, the oil giant's opponents told a federal judge…Alberto Guerra is a star witness for Chevron in its bid to delegitimize the judgment ordered against it by a Lago Agrio court in 2011. That decision…leaves Chevron on the hook for oil pollution that has devastated a rainforest community in Ecuador…Guerra, who was the first of many judges in Lago Agrio to hear the environmental action…, testified last week that [Judge] Zambrano essentially rubber-stamped a ruling written by the villagers' attorneys…Guerra also testified that he was paid $1,000 a month by Zambrano to ghostwrite orders for him…Taking and giving bribes was common for Guerra both as a practicing attorney and a judge, he said. [also refers to Texaco (part of Chevron), Petroecuador]