Ha ha, I don't think I've ever started a discussion as long as this on any forum ever!
As for the offending spider, it buggered off! I assume because of the sudden interest in it it felt it wasn't in a safe enough spot anymore.
While this SOUNDS like the best thing, i.e. no death to plant, no human to spider interaction, it actually scares the hell out of me cos now I don't know where it's new hiding spot is.
On the upside, I am now armed with a spider spray and some good gardening gloves and boots, so when I find it.......