One wonders why pax evacuating the aircraft didnt slide down the wings following the markings there just outside the o/wing exits. It's still some height but with the flaps fully extended, should be easily done especially if trying to escape danger.
As for it being a "distinctly amateur" performance from the cabin crew..... Well the forward doors on a 737 are vey heavy and difficult to open in normal operations never mind with the added drag of an attached emergency chute. Cabin crew did the right thing by re-directing the pax away from an-unusable exit. Everybody got out ok. Lets remember that.