Happily, all remaining fish have survived and are looking healthy. I was worried about one male swordtail, but then realised this is because he'd spent the last 2 months courting one of the females, who responded to the stressful conditions by turning male. As you do.
[Really. They do.
http://animal-world.com/encyclo/fresh/livebearers/swordtails.php] The newly-male swordtail isn't quite passing - his sword is a bit flappy and his gonopodium looks rather hastily constructed out of her anal fin - but you can understand why his amour ended up hiding in a plant for a week and hyperventilating...
Jilted swordtail is now at least socialising with the other swordtails.
The Aquarium - like EastEnders only better looking and with more realistic plots!
Link to pics of a male (with sword) and female (no sword and with anal fin)
http://www.fishkeeping.co.uk/modules/newbb/viewtopic.php?topic_id=992&forum=12&start=20