Were they under orders not to shoot?
Remember, in India everybody but everybody is dirty poor and bullets are expensive. Presuming nothing ever happens on the job the cops must be under tremendous pressure to simply sell their bullets.
Then there's the pretty basic issue of firing a pistol at a guy with a machinegun.
Without good cover (and I don't mean a board, or a plaster wall) that is foolhardy and would almost never result in success against the guy with the machinegun.
This issue will undoubtedly be subjected to public review and the answer is going to be more along the lines I suggest than that the cops were simply cowardly, although that could be true in some cases.