Rich, your friend needs to be truthful if you are to get out of this unscathed. I find it difficult to believe he didn't receive any notice from the insurers. They usually write more than once in cases like this, and not every letter is going to go astray, unless his address details are registered incorrectly. He needs to check what details the insurance company hold, or held, on the policy. He would, or should, know what is coming out of his bank account. If, as you say, he couldn't afford the payments, he cancelled the payments, and allowed you to drive it knowing it was uninsured.
Hope you can get it sorted, but get your friend to 'fess up.
John.