Can anyone tell me if this is an error?

As in the head of the Emu is off?

Hard to tell from the picture.

Look at this:

https://www.ngccoin.com/price-guide/world/australia-florin-km-60-1956-1963-cuid-1048409-duid-1217170

Velkommmen til Numista, although you're not really new.

If you make a hi-res image coin it would be easier to judge about the head.

here is yours against a NGC coin

It looks different, but please supply a better image to compare.

Paa gensyn