My first thought was that, for whatever reason, the breweries in question are using dairy equipment and thus get a dairy hechsher. But the KAA web site lists the following in its key to designations:
D = Dairy
D-CY = Dairy/Chalav Yisrael
P = Pareve
P-DV = Pareve/Dairy Vessels
So if they have the P-DV designation (not all authorities distinguish this case but apparently they do), does this mean that it's always used when possible and New Zealand beer really does have dairy in it? Or are there cases where a kashrut supervisor might say "dairy" when it's instead an equipment issue?
My immediate question is about KAA, but if there are broader principles involved about how kashrut certifiers make these determinations, I'm interested in hearing htem.