From the article it describes the ADA programmer as: "This developer had very limited Ada experience, having written only one Ada program, consisting of approximately 5000 lines of code, while working for a previous employer."
One of the key points of the article is that the code produced by the inexperienced ADA developer beat the experienced Assembly developer. I think a lot of people will struggle with this (because they think "well, logically the code gets turned into assembly anyway when it is compiled, so a sufficiently advanced assembly programmer _must_ be at least as good as a compiler), but the same claims (high level languages beating assembly) have been floating around for years.
In this case study at least, jumping straight to assembly (for size/performance reasons) turned out to be a premature optimisation of the sort we should avoid.