But that's the actual problem, that nobody else tried to verify the data themselves before accepting it into the field. If you could reproduce the algorithm in the paper without the source code, why couldn't they?
And while it may have meant that the Met Office's code would itself have been fixed faster, I don't buy the idea that having the code available necessarily would have meant the errors in the resulting data would have been discovered faster. That would imply that people would have actually dived into the code looking for bugs, but we've already established that the people in the field are bad programmers who feel they have more interesting things to do. Why isn't it just as plausible that they would have run the code, seen the same buggy result, and labored under the impression they had verified something?