Weird paint lacquer failure

[HPsauce]

Yesterday while washing the S8 I noticed a chip on the bonnet, quite obvious as it looked white, so presumably through to the primer.
But when I was wiping over that area a whole patch of lacquer coat came off, about the size of a large egg! It was as if the damage had somehow caused it to separate and peel, though I hadn't noticed anything before.

I just carefully cleaned the loose flakes away and could see the "peeling" extended further but just left that as I didn't want to damage the colour coat by picking at it.
When it dried the colour coat looked quite matte, not at all shiny, or is that some intermediate layer?

To protect it I just filled in with lacquer from a touch-up pen (no lacquer spray to hand) trying to make sure it sealed up to the existing lacquer. It's not pretty as you can see in the picture, but less obvious than you would expect. At a glance it just looks like a bird splat! The initiating chip is at the very bottom of the damaged area though not very obvious due to reflections.

Is this unusual and will it require a full respray of the bonnet?