Classic public and private sector PR lines. Councils do it. CEOs do it. Politicians. Civil servants. Headteachers.
When do they ever get their P45 for it? Never. "Lessons learned" is a proxy for "We sound like we care. Today's news is tomorrow's chip bag buddy. You'll forget about it in six month and I'll carry on regardless, pissing myself laughing that you're a mug. Laters"