Reviewing the individual formulas in an excel report is psychotic. Normally what I would do when checking someone elses work for errors is spot check a couple of the values in a column and calculate them by hand to see if they matched up. Either that or just implement the step myself in excel and see if I got the same output.

That's a lot like reviewing someone's regular expression. Like I'm not going to read through a 100 character regex to see if it matches semantic versions, I'm just gonna pull it up on a regular expression tester and see if it does what it should.