Just speculation, but skydivers have a culture of being very skittish about aircraft- with some justification given the sh1t-boxes often used for skydiving. I know people who've exited at 500' because an engine burped.
MAYBE the "difficulty" involved something audible to do with an engine, and a jumper deciding he wanted to be under his parachute. If so, awful that a passenger was also subject to that decision.
Another factor is that jumpers are supposed to use single-point restraints in the aircraft- I've seen exactly one person do so- a CASA inspector!! The fact that this is a requirement that has been routinely ignored and never enforced in decades is a bit of an indictment.