hopefully averted a crisis??

[Delphinus]

Caulerpa sporulating on you ("going sexual") isn't really the end of the world, but it is a nuisance. It's not great of course either, so if you can avoid it, that's better. But usually a water change and some carbon does clear it up and the new growth sucks back any nitrates or phosphates that get released.

It's better to be proactive on the pruning so that if any does go on you, only a little bit as opposed to a lot would let go on you.

Unfortunately there are other reasons beyond sporulation that caulerpa, particularly in a main tank, is undesirable, such as allelopathy (for lack of a better way to describe it, think "chemical warfare") - allelopathy is one organisms ability to inhibit growth of a neighbouring competing organism - and according to Borneman anyhow, caulerpa can inhibit growth of SPS. So, it's better to keep it contained in a refugium separate from the main tank (even then, probably not a 100% defense, but, at least it's contained somewhere).

You're right, it will probably come back. You can pretty much decimate the stuff by going pruning crazy on it and it will undoubted still come back.