Of course they haven't - they've been exceptionally well trained by lawyers to avoid anything that might land them in hot water. However, Bracken did flag up the issue after after the series, and got howled down by indignant English bowlers. Trescothick himself has been pretty clear that he knew...
For this incident, directly? I think CA has it spot on. Warner to blame across the board, Smith to blame for not stopping it once he was aware, Bancroft to blame for not refusing to do it.
Ultimately, though, if you dig deeper ... the ICC is to blame, for systematically failing to deal with the...