Use sumproduct to produce text with row and column reference in Google Sheets

Is there a way to extract the text comment in the error produced by sumproduct in the following sheet? I expect C9 and C10 to be "Comment1" and "Comment2". This appears in the error message. Either a direct way to get the desired text or to extract the text from the error message using some JavaScript will be fine.

Here is the test sheet.

https://docs.google.com/spreadsheets/d/1aq4afUw29CxdOM4Yp9dgZw2wdJto8H343YMTJLXG-qM/edit?usp=sharing