As Western woods stated elsewhere, few language skills are needed to understand that someone is agreeing to, or not agreeing to have sex. Even gestures will suffice. And clearly the cabbie understood English well enough to get his license and do the job. However, understanding a legal proceeding would require a high level of language proficiency.

No one should be drawing negative conclusions from the court providing the accused with an interpreter. The fact that people appear eager to do so indicates bias.