I suppose crossing a CMA picket line by CWU members comes down to peoples own principles.
If you believe that no picket line should be crossed, then you wont.
If you believe only some picket lines should be honoured then if you think you have a valid reason you'll cross.
If you can't bring yourself to support the managers because of their past actions then you'll cross.
Its ultimately a personal choice and although managers routinely cross our picket lines I will still not surrender my principles based on their actions. My sense of honour is based on my own actions, not others, and I will NEVER cross a picket line even if its manned by the minions of Satan.
However, I still think its a personal decision and I will respect, if not understand, why people would cross.