That's exactly what happened though and no one bothered mentioning this to this reporter. I was in the post mortem for this event, the alert for database disk

That's exactly what happened though and no one bothered mentioning this to this reporter. I was in the post mortem for this event, the alert for database disk space was piled in to 500 other alerts incorrectly assigned to a rotation notorious for being the most painful in the company. The alerts escalated through to an infrastructure manager and then to an at-the-time director of engineering, none of whom acknowledged the alert themselves. The alert itself was also of the "disk is 90% full" variety rather than "at rate of growth the disk will be full in an hour and by the way this is the master db". The former wouldn't be a need to panic as you'd have at least a day to resolve it, unless someone is back filling large sets of data.