[pick me]
The article does not explain, specifically, what the problem was but all it would take is for a junior staff member to misunderstand the accounting treatment or classification of a particular asset or liability.
For example, suppose we have a long term debt interest of 1,000,000 and instead of amortizing the debt over 20 years ($50,000 per year) someone calculated the amortization over 5 years ($400,000 per year). That is a $350,000 error to the bad. If someone discovered the error they could reverse it and realize significant savings.
The same could hold true for inadequate accruing of interest revenue. Any accrual is simply a calculation. An estimate so that you match your monthly revenues and expenses (matching principle

) If you miscalculate your accrued interest revenue, again, correcting the mistake would result in signifcant revenues and, therefore, improved bottom line.
Make sense?
Yes, I am a number nerd and, yes, geeks freaking rock! WOOT!!