HT are exempt from the 1,269 hours per year that MPS/UPS staff are subject to (although bear in mind those are directed hours, so it doesn’t account for any out-of-hours work, of which the hours are too numerous to mention).
However, their salary is for 39 weeks, spread over 12 months for payment purposes. Despite this, I’ve never met a HT or classroom teacher who didn’t spend a significant amount of time working in all of their ‘holidays’ (said as a former teacher).
If there is a ‘serious incident’ during the holidays, HTs get to know about it (I’ve been in schools where a parent has died in the holiday - we knew, so could support the child - and several cases of DV or SS involvement, so that again the child could be supported). They’re not uncontactable, just not uncontactable to parents.
My HT friend - who ‘broke up’ on Friday - has been in school today, and will be tomorrow, catching up on paperwork they just can’t get done when children/parents are in, and it needs doing. Said friend will then take a couple of weeks ‘holiday’ (albeit still checking emails and responding if necessary), before switching back into work mode and getting ready for back to school.
Whatever your issue with the HT in question, it’s personal, not professional. Leave them alone and let them have a few weeks peace and quiet.