The article says the issue, discussed with Yle (the content provider), was fixed mid-flight - it doesn't say anything about a fix being pushed. For all with know it might not even be the code, maybe it was a property in the JSON-data of a news article that was changed from left-aligned to right-aligned?

Also - no matter if it is relevant or not in the case - being able to deploy and update fixes to a system in production without anyone noticing is a testament to good system design - and even a requirement in many cases.