McCoskers Flasher Wrasse sudden death

Did you get a male or a female. I was looking @ bluezoo and this is the next fish i was wanting to buy and didnt know if i should get male or female.

 

I just did a post the other day about my Mccoskers, I buried him under a rock for about 4 hours when I was changing my rock work. I thought he was dead too, went white like you described. But he did come back the next morning and was fine...
Good Luck, hope yours pulls through!!

 

I got male. Male displays brighter color during mating, if you can find a pair (or two females - one will change to male).

 

He is gone. Sadly confirmed.

 

Sorry to hear, just happens sometimes. Lots of people don't think a slow acclimation is good for fish. All of the online stores I've ordered from recommend an acclimation period of around an hour at most.
Not that I think this necessarily had anything to do with your problem but something to keep in mind.
Sometimes fish don't handle shipping/tank changes very well, just a fact of life at the moment unfortunately.
Your fish's behavior was really weird since these fish don't use the sandbed when spooked generally, they hide in rocks/holes etc but don't go into the sandbed.

I would highly recommend at least a pair if you have the room in the tank, a trio of one male and 2 females is recommended by a lot of people, it's a bit more natural since these fish live in harems in the wild.
Having a female around will ensure your male's colors don't fade and you will get to see some really interesting behavior between them.