Alas, Saeedkhan, we would like to learn from the unfortunate experiences of others as soon as possible, especially as in the case of some jurisdictions the official results appear very slowly or sometimes never at all. This is as true of the AAIB as in many Eastern countries.
Aterpster says that according to US rules, commercial operations cannot begin a circle to land unless the PREVAILING visibility is greater than 2.3 nautical miles. It seems to me that with monsoon conditions veiling the hills, the prevailing visibility was dodgy and the circling approach should have been refused. Regardless of the skill or experience of the pilots.
When in doubt chicken out works better than sweating in any kitchen.