Unless the aircraft is controlled by a maintence controller the the person (lame) that signs of each cat is and the lame co-ordinator will be deemed the responsible as we'll as the owner.
Yr Right, this would contradict CAR 41, for Cat B maintenance.
As a LAME certifying in a category I don't see the log book only the work sheets, so how could I be responsible for something not on the worksheeets?
I think you are right about SBs, if an AD is raised refering to the SB it becomes mandatory as well.