The 2011 version of MAA regulation RA 1210 makes two very clear statements;
"The goal of risk management is to show that safety risks can be tolerated and are at levels that are ALARP; merely identifying and mitigating risks is not in itself sufficient.
AND
"ALARP is essentially the "stopping condition" for risk reduction, so justifying and recording how this is reached is an important and vital step in safety management. A DH is required to make an argument that risks have been made ALARP; however, the validity of this argument can only be decided definitively by the courts, if an accident occurs." [My emphasis]
As AVMs Bagwell and Atha both signed off in 2011 to say that the risk of collision was Tolerable and ALARP, and an accident has occurred, then it is mandated that they should stand up in court and justify their decisions. The place to do that is the FAI.
DV