You cannot forge game mechanics messages. If the game tells you that something happened, then it happened. The only way to trigger the "someone altered the accounts and stole money" or whatever it is that it says, is for the banker to cook the books. The character can try and spin it, or pass it off on someone else. But as a player, you can know that the *only* way for it to happen is the banker.
There have been ideas for making it so that there are multiple ways to get the same message, but I don't know how many things this applies to. So far as I know, there is a delayed-buy option for buying lordships that looks just like the spontaneous uprising and naming of a random noble as lord.