One thing must be emphasized. Whichever community was guilty for whatever excess pleads amnesia or seeks revision of history. Better yet, they would like the clock to start the day after….
Thus BJP is proud to state that Gujarat has been riot-free post Feb 2002, Congress has really cared about Sikhs following Nov 1984, Pakistan has been a well-wisher of Bangladesh since Jan 1972……
And yes, certainly no one has been conclusively determined to be at fault for the state-backed terrorism in August 1946, for the 10,000 deaths in the Great Calcutta Riots following the call for Direct Action by the Muslim League. As is the norm in South Asia there is a Hindu truth (the villain was the ML govt of Bengal headed by Hussain Suhrawardy) and the Muslim truth (majority dead were muslims, hence the riots were the fault of Hindus). FWIW there is a comprehensive account of the riots at the link noted below which tries hard to be fair.
An interesting observation- even though the riots during partition were quite violent in Bengal, there was no exchange of population, as had happened in Punjab. It was post 1965 and mostly in 1971 that mass Hindu migration took place from (now) Bangladesh.
Amidst all the competing truths that are out there, the following truths are undoubtedly true-
(1) India will be a hostile place for muslims going forward, while in Pakistan and (to a lesser extent) Bangladesh you can be in trouble if you are the wrong sort of muslim, and
(2) Hindus will in time disappear from a third of the South Asian landmass.
Link (1): http://www.massviolence.org/The-Calcutta-Riots-of-1946