So, we were/are left with a grey area as to WHO is responsible in this scenario
As SLF I would have thought it would be spelled out in SOP's ie Duty managers job description and responsibilities, ditto gate personnel, cabin crew, front seaters. Certainly seems strange that such large organisations with possibly multiple hundreds of pax involved responsibilities of their staff are not spelled out. Can end up with too many chiefs thinking it's their responsibility to take charge of a situation, issuing orders, and no one left to carry out the necessary action.