Another way to look at MSSI dividend. The record date was 29 September, the Payable date was 8 October and the Exdate was 14 October.
So if one bought stock prior to 10/14 but after the 9/29, the new investor was purchasing pre-split shares because the split did not become legally effective until 10/14. (if you use the ex-date as legal precedence over the payable date). In that case, the company does not owe you the split shares but the person that sold you his pre-split shares prior to the ex-date.
I'm not sure if that makes sense but I guess the bottom line is whether the SEC will recognize the Ex-date or the Payable date.