“I wondered, could they say ‘I believe in one, holy catholic and apostolic church’ and not be, well, Catholic? “
I think all Christians believe, and most state, that they believe in one holy catholic apostolic church.
You might note that “catholic” is a small c. We aren’t confessing in one holy Roman Catholic church. There is a difference.
As defined thus:
ADJECTIVE:
1. Of broad or liberal scope; comprehensive: “The 100-odd pages of formulas and constants are surely the most catholic to be found” (Scientific American).
I do believe in one holy apostolic catholic church. It consists of all true believers from Abel to present; hopefully including Adam and Eve? In short I don’t believe my local congregation to be the only believers on the planet.
So I don’t find our belief in one holy apostolic catholic church to be inconsistent at all.