Ok, I'm only an engineer, and a retired one at that, but the way it seems to me:
1. The cowls on both engines were closed but not latched.
2. It appears to be difficult by a visual check to establish whether they're latched. And without using some banned implement like a screwdriver a physical check may be next to impossible.
3. Result - a serious incident which could easily have resulted in a catastrophic accident.
Ergo, the manufacturers MUST design a mod which makes an unlatched cowl impossible to miss. Next time - and without some positive action there will be a next time - we could be looking at a hull loss with multiple fatalities.