Some years ago, I was presenting in China in front of a government audience.
As I had a local official assigned to simultaneously translate my speech into Mandarin, I assumed that no one in the audience actually understood English. But, to my big surprise, my presentation got interrupted twice by the guy who seemed to be the highest in rank in the audience. He kicked-out the interpreter on duty and replaced him by another one he had on hand.
This man perfectly understood what I was speaking about in English –even though it was addressing a very high-tech topic– and decided that the Chinese translation was not accurate enough.
Never underestimate your audience!