That is not how it works in India, the civilian leadership decides and military leaderships executes.
I think you meant, Kaul failed to apprise the Civilian leadership about the "complexities" of such a venture?
This is slightly misleading. The civilian leadership takes decisions at the policy level, at the geo-political level. It does not decide how many men are to be posted, at which locations, which units are to be deployed, what tactics are to be used, who should be general officers involved and field officers, and the like. Those are strictly military decisions.
Please remember that behind this massive leadership failure, there was a third factor besides the political/civilian factor and the military factor. This was a situation very largely created by an ego-maniac, the ranking police officer in the country with a rank equivalent of Lt. General, Mr. B. N. Malik, in those days Director IB. In 62, all intelligence activity, internal and external, political and security, was combined in one body, and Malik was the undisputed monarch of the establishment. It was his consistent and sustained advice, based on unknown evidence, that China would do nothing to resist India. This was a considerable influence on the increasingly bellicose attitude of the Indian leadership.
Second, Kaul always had the option of informing the political leadership of why, professionally speaking, the Army should not have taken up patrolling border guard duties, and also why it should be prepared for a robust response from the PLA. However, it was an option only under the very peculiar conditions of the times, when the Chief of General Staff spoke to the Prime Minister and the Defence Minister, rather than being a totally silent supporting staff officer tasked to work on the projects and activities discussed between him and his boss, the Chief of Army Staff. General Thapar's acquiescence in the goings on was a very sad end to a good military career.
Third, in 71, the situation for the Bangladeshis was quite desperate after Operation Searchlight. It was only then that it dawned on the Indian leadership that this was not a problem that was going to go away, it was not the Language Riots, it could not be dispelled by patience and tactful administrative handling by the authorities in East Pakistan, not even by a mild show of force and a couple of occasions when a mob would be fired upon. It would remain and take on sinister dimensions as time went on. When the then prime minister asked her COAS to take action, he refused: (i) no plans were ready for an intervention in East Pakistan; (ii) there were no troops assigned for East Pakistan; (iii) starting a campaign two months before the monsoons was not intelligent behaviour or good military planning.
He therefore insisted that we wait until the GOC-in-C Eastern Command, and that Command's Chief of Staff, both completed their job of planning and re-grouping troops. This took till November 71. Except for a military overturn, aand another really stupid bit of planning, it was quite a good plan.
Telling the pols something can't be done is possible; telling them what is possible instead has their entire attention.