
Who is at fault?
Suppose person A is the one who has to get the final changes back to person B. Now there is an unreasonable delay from person A side and person B thinks person A is responsible enough or has the integrity to communicate changes once finalized. So Person B does maybe just 1 follow up and doesn’t chase Person A.
With the delay, who’s to blame ? Person B has not been able to start his work as he’s waiting on Person A.

Who owns the deliverable? If person A is one of many people who contribute / review, then it is owners responsibility to drive closure, and if person A is a road block, he should call out. Some people need more reminders, that's just the way it is... If everyone did their job without followups or reminders, half the management cadre would be redundant

Person A owns the deliverable. Person B has called it out just once. Ya the followup part is what I am trying to understand that how many times is enough so that Person B does not hold any blame

Person A and B's Manager.. this is where managers play a role.

Nobody is at fault, it's a dependency issue. Person B is dependent on Person A to handover the tasks. Ideally, this would be reviewed by POs and ALs in retrospective to ensure another delay doesn't happen.
