This decision vacates an arbitration award for misconduct by the arbitrator in discrediting the defendant’s primary witness’ testimony because she askeds for an interpreter during the arbitration though she had been in the US and conducted sophisticated business dealings here for decades. The arbitrator’s credibility finding rested on unacceptable misconceptions about English proficiency and language acquisition and gave rise to a reasonable impression of possible bias. One can have economic success within foreign communities within the US without becoming proficient in English. Helping others even less proficient doesn’t show that one is sufficiently proficient to understand and correctly answer questions at an arbitration hearing in a complex business dispute.