help me settle a debate
going to keep this as vague as possible to limit any bias.
Person A starts a load of laundry in the washing machine. Person B goes to move it to the dryer partway through the day, notices that a pull up must've been in it, and that it had made a mess (pull up beads filled with water, not poopy or anything)
person B had toddler load the hamper and some of the pants had unsoiled pull-ups in them, later in the day person A ran a load of laundry and missed the pull up stuffed in the pants, person B noticed the first pull up and forgot they had toddler load the hamper so they forgot to check if another pull-up had been missed
Person B then finds the diaper, removes it, and goes to restart the wash. Later in the day, Person B asks Person A if they can go check the laundry and see if it got cleaned after the pull up was removed. Person A says that it didn't look clean, and ended up finding another diaper in the laundry.
Person A agrees to their fault in putting the pull-ups in the laundry in the first place since they started the load initially, but makes joke about Person B not checking to see if theres more pull-ups after finding one. this escalates into a fight. Person B doesn't understand why they should have assumed there was a second diaper after finding the first, and blames Person A entirely.
From an outside perspective, who do you believe is at fault here? A entirely for not seeing the pull-ups or both because B didn't check if toddler left more in ?
edited to add context (some thought we were throwing poopy diapers in hamper)