I was thinking its shape was similar to a possum wrasse but the colour is wrong. I'm pretty sure I've seen wrasses similar to your pic but for the life of me I can't quite place it. I keep thinking its along the lines of a juvi maori wrasse but I'm not sure. Did he look like this?
Slender maori wrasse - Cheilinus-orientalis
or this: Speckled Maori Wrasse Cheilinus arenatus
