This is very unusual in all respects. The Purser on Short Haul normally does not do the pointing. a crew member does that so the Purser would be free at this point to deal with whatever issues arise. It sounds as thought the CE pax did not tally with the headcount but the headcount may have been correct in total.

Safety briefings are not for the crew to pick and chose and we give manuals with scripts as people do forget and overlook things. If the demo was incomplete the Captain would be told and he would hold short. There might be a to-do later particularly if a slot time was fast approaching but safety is paramount. Frankly it is almost as bad as forgetting to arm the doors or disarm the doors.

I will say this. The less crew there are the more likely this sort of slip can arise - but what I do not understand is that the crew would not fulfill this as its so built in during training and is every single flight.