I think someone is trying to cover their ass. Think about how this story could have been written: the WSJ reaches out to current and former employees and writes what they say. Those cyber security employees are already feeling the heat and want to preserve their reputation, so they throw someone else under the bus.
This was an inside hack by a former AWS employee. It was difficult to protect against. I can't fault Capital One here as much as I can fault AWS.
There will always be tension between the Security team and the rest of the company.