“Jesus said to them 'I am'" (John 18:6) - Did Jesus break a taboo here?

In the following verse, did Jesus in fact say the word, the name of God, that no Jew would dare to say aloud at that time? > As soon then as he had said unto them, I am [he], they went backward, > and fell to the ground (John 18:6) If yes, why was He not tried for that before the high priest (there were so many witnesses after all)? If not, why then so many say that here He was quoting Exodus 3:14 (which means He DID pronounce the forbidden word)?