I'd like to take this conversation back to when the aircraft was 10-15 miles out.
If we consider that at about 6 miles out (depends on if you are using RNAV or ILS and which runway as the basis of your GS and intercept point) you want to be at about 2000' . They are reported to have been at 3500' at about 5 miles out.
Granted, I am not familiar with PIA's SOPs, so this is a bit of a guess based on what I observe when I am (on a rare occasion) in the back of an aluminum tube.
When they were 15 miles out (or so) my thought is that the crew should either be in the process of configuring the aircraft for landing, or already be configured, depending on the situation at hand. Gear / flaps / various checklist items, etc.
What happened in the intervening ten miles?
Last time I was in the back end of a passenger jet, they had the gear down about 10 miles or a bit more from the airport. What was going on in this case from 15 miles out to them arriving at 5 miles out well above profile?
Will be interesting to see the FDR info, and see where and when configuration changes actually occurred. (Or if they did)
PJ2 alluded to a human factors element, and I am thinking through a CRM problem: in the past three months, how often have the two pilots flown and have their habits/processes gotten rusty due to the curtailment of flying in general. The old currency/recency thing has me wondering.
True confessions time: more than once I had either a crewman, co pilot, or a tower ask me to check my gear on short final. With good reason.
It can happen to anyone if a particular habit pattern, or rhythm, gets disrupted as one gets into the terminal area.