Weird one Michael! Very interesting find... Heino, is this Amanita because it has the little light blotches all over it just like the red ones do? I think there might be some death caps that have shot up just up the road from my place, I might go and get a couple of sighting photos now... You've inspired me to see what they could be.
Irregular blotches that, when you look at them closely, show themselves to be bits of tissue sticking to the cap meanyou almost certainly have an Amanita (but there are also smooth-capped Amanitas). The word irregular is significant. Those bits of membrane are remnants of a universal veil, a skin that initially wrapped around the entire mushroom at the button stage and left remnants when the expanding mushroom broke that veil. There are a number of genera, with no universal veil, where the outermost layer of the cap itself breaks as the cap expands. This leaves you with regular, concentric rings of scales - denser towards the centre because, as the cap expands by swelling of cells, the greatest expansion is towards the margin. Often (but certainly not always) the skin cells are of a different colour to the cells of the underlying flesh and you see that colour as solid colour at the centre. Check out Lepiota on the Canberra Nature Map for an example.