Possibly this could be considered a Handsontable bug. If you change data while in edit mode, the editor doesn’t track with the change and can result in editing a different row or even adding a new row. Example here:
http://jsfiddle.net/kv76qcd5/6/
In this case I delete a row 5 seconds after you enter editing. The deletion shifts rows upward, resulting in the edit applying to the row below, or adding a new row if edit was entered on the last row:
What can be done about this?