Nah, an overbearing parent smashing a phone to “teach them a lesson” isn’t an “accident”

Since Apple make no distinction between “malicious damage” and “accidental damage”, then everything is called accidental. However, there are times where accidental damage is covered under warranty (or rather, a “service program”) when there’s an issue that’s widespread enough that is attributed to a manufacture or design defect – the warping of the plastic on the bottom of the Late 2009 Macbook comes to mind.