Blizzard does record and detect if you are even in voice chat or not in each match. By not participating in team comms, you CANNOT be punished for Abusive Chat. Now if you are abusive in text based chat, there will be verifiable records for that.
Remember it has been confirmed that all Abusive Chat actions are verified by a human being:
As a bonus tip, if you are being abused in text based chat, type /hidechat to remove the chat dialog. It will not appear again until you hit the Enter key.