How was the Sepoy Rebellion a clash of cultures?

The most obvious way in which this rebellion came from a
clash of cultures was in the disputes over the army's new cartridges.  These cartridges
needed to be bitten before they could be fired.  Rumors spread among the Indian soldiers
saying that the cartridges were greased by the fat of pigs (forbidden for Muslims to
eat) and cows (sacred to Hindus).  This would have forced both religions to defile
themselves whenever they bit into a cartridge.

This shows
that the mutiny came from cultural conflict.  It came out of the belief that the British
would defy Indian cultures and force the men to defile
themselves.

But why did this rumor gain credence?  Some
scholars argue that the British had allowed this through their efforts to push
Christianity and to do away with things like the "sati" -- the burning of Indian
widows.  If this is the case, then the mutiny came out of a clash of cultures because
the British were trying to impose their culture on the Indians.