It is up to the store. You can't worry about the unknowns. A civil damand letter is an attempt by the store to extort you for money to pay for their loss prevention procedure. Just let it go for now and if you receive a letter then decide. There is no way to predict how aggressive a grocery store will be.
In Indiana, there is precedent for stores to send civil restitution letters for restocking fees. However, as indicated by another attorney, do not fret over when the demand my possible occur. If received, consult with an attorney to avoid and 5th Amendment implications nd make decisions based upon your attorney's advice.
I don't think anyone here can tell you if you will actually get one. I generally advise clients to ignore these civil demand letters. You don't owe them anything. In order for you to owe them something they would have to sue you, (in some jurisdictions prove damages which they most likely couldn't do), and win. Even if they could win, the cost of pursuing this is substantially greater than any amount they can possibly recover so they usually don't. They send out these letters because it doesn't cost much and they are hoping that you don't know better and simply send them the money. Nothing will happen to you if you don't pay it. Take a look at an article in the Wall Street Journal at the link provided below.