This got me taking a second look at B. cavernatum because I'd only seen them with a lot more "warts" than this, but it seems at least some populations of specimens have lower numbers like this.Looks like Bundosoma Cavernata or warty sea anemone based on the collection location, size, and the spots on the column.
So, yeah, I'm inclined to agree that it may be Bunodosoma cavernatum - at least if you're measuring the tentacles and oral disk for that measurement of just over 3 cm.