Clearly written by someone without any real world experience. Daily checks and plots, and daily phone calls and meetings.....

But how we start by explaining this. Does the author expect us to believe they were using Excel 2003?

"I’m not going to complain about Public Health England (PHE) using excel to merge the test results from each test centre"

What actually happened, then perhaps we move onto solutions.

(The solution most likely being some sort of Hamming code/check sum, the number of cases is also included with the data for instance)