I need to respond when the player's armor or equipped weapons break, on the client side. 

 

I am aware of PlayerDestroyItemEvent, but that only triggers when a tool or weapon breaks while used on its intended material - it does not fire for armor, or eg. a pickaxe that breaks while mining sand. 

There's LivingEquipmentChangeEvent, but that also triggers when the player changes their armor on purpose, and doesn't cover tools or weapons.

I tried LivingAttackEvent, LivingHurtEvent, and LivingDamageEvent for the armor, but they also do not always fire when the player's armor breaks (for example, if the armor breaks due to a cactus but blocks all of the damage).

Lastly, monitoring the player's inventory every tick will also not work, because as with LivingEquipmentChangeEvent I can't distinguish between the armor/tools breaking and the player just unequipping/dropping it intentionally.

 

I did find ItemDurabilityTrigger, which appears to do exactly what I want (though I'm not sure about server/client side) ... but it's not an event, and therefore seems to require that I do some reflection/ASM stuff, which I am wary of.

 

Is there a way do this?

ItemDurabilityTrigger is an ICriterionTrigger for use with advancements.

There is not a Forge hook for this. But you could, conceivably, add a listener to the existing trigger, but keep in mind this is a server side effect only.