Same deal as some eager student shoving an Excel Spreadsheet in my face and telling me his "numbers are correct".. Well yeah -- but you solved a problem that never existed ....
Beware climate change spreadsheets.
First, "GIGO" - Garbage-In, Garbage-Out".
When shown one in a link if you can open it with your spreadsheet program try doing a "select all" and change the font colors to something other than they seem to be. If they're black, for example, turn 'em all red.
Then look at it again.
You can cause a spreadsheet to make it lie just by putting in figures into it using any font with the text color set to white. That's because the default background for all cells is white and white text will not be visible on screen or printed but the contents of those "invisible" cells WILL be felt in the summaries. If you don't want to change the text color then, instead, change the cell backgrounds to something like a pale blue. Easy enough to make the corrections and then return it to normal.
I had this tried on my by an unscrupulous seller in a real estate deal some five years ago. Had he been satisfied to try to steal just a little I might have smelled the rat but he was a little too greedy and the sheet didn't "eyeball" just right.