We'll need a citation for that.
I recall reading it long ago. It was not a rules source, it was a Q&A or Con panel or some such.
Nonetheless, my assertion stands. If the program has a chance to be successfully written, from scratch, in one week, it can't be that hard. Not seven days of desperate 12-16 hour labor, not a modest overtime of five tens, but a standard 40-hour week.
Debugging is a be-atch, and the odds are only 1 in 6. But that's a matter of debugging, not coding. If the math is known, the coding is equally known. In fact, there would almost certainly be a math function library that takes that problem out of your hands. It's the typos that get you, for the most part. Then it's properly conditioning variable/value passing (preventing overruns, overwrites, data type errors, and so on).
This 10+ roll for completion and the 11+ roll for manifesting a hidden bug is for programming from scratch and doesn't account for "cheats" such as decompiling the flawlessly working code to uncover its secrets.
I would only say that MM isn't a programmer and likely didn't have a good grasp of coding and debugging time requirements. If it can be written in a week at Comp-3, it can be written in two weeks at Comp-2, and a month at Comp-1. Overtime can compress that greatly, especially when stuck in a space ship for a week with nothing else to do.