Retirement tax questions

So, I have a couple questions on this issue.  Was TurboTax at fault for the incorrect formula on the MO-A worksheet, or was the MO Department of Revenue the root of the situation?    Also, I filed MO return on the date MO opened up filing, TurboTax said all was fine, and was very (pleasantly) surprised yesterday when my refund was much higher than what I had filed.  But, why didn't TurboTax give me any heads-up on the issue and that they had refiled or corrected my return?  I knew nothing of this until the refund amount showed up.  Thanks.