I noticed this remark in the ACSC yesterday concerning the 50th Anniversary of the Country Women's Association issue:
"A mint block of 4 has been reported showing the magenta printing omitted from the upper pair, and largely omitted from the lower pair. The error mainly affects the women's [sic] face and neck, which appear white and also increases the intensity of the green colouring of the stamp. Listing is suspended pending verification of the genuineness of these stamps."
Source: Decimals I 1966-1975 (2002 edition), p. 9/249.
I believe that this is what the stamp should look like:
I checked my stockbooks a found a copy of the error referred to in the note. It's in MNH condition:
I wonder if the ACSC were ever able to verify this error. If not, here it is!