The company thinks it liability will be reduced by renewing the no smoking instruction. Perhaps they think the liability can be passed on to non complying captains. Should those concerned be more carefully considering their position? They could be invalidating relevant insurance by not informing insurance company of this situation. Even this PPRuNe post could be part of the evidence that they should have reasonably known their instruction is ignored. Its a bit unlikely that offending captains have valid insurance if a F/O takes civil action. Could they be in a position where savings, house, car and retirement funds are at risk?