From the bugs described in the article, specially the one a person could withdrawal from another account to its own account, I believe better test libraries could help.
Normally people develop tests using the same input data from beginning to end of test execution, since it becomes cumbersome to use different test data for input in the same round of test execution. Mainly because how these data come from fixtures.
I don't know if this is a good example of the value of testing. This 'mistake' strikes me as so colossal that the idiot who allowed it to happen would not be saved by writing tests.