No idea, since your download does not contain all the source files. You have some weird masking stuff going on in there and potentially there may be something going on with the PS Live 3D transparency, but that's all anyone can guess.
i've been back to the PS forum and they say..."it's not us, if you can't see the tinge in PS ( which you can't ), it must be the AE boys !"
One thing I noticed from your comments: you mention wierd masks. There is no mask in the PS file. I think the import of a live 3D file into AE has created this mask but it covers the whole canvas - including what shouid be transparency. If I delete it ( or decrease the opacity ), the tinge diaasaapears ...along with the coin ! Does anyone know where and why this mask is coming from ?
Here is a shot of the layer options open to go with the screen shot above. Could it be something in the material options ? I've tried playing around in there to no avail. I think it is something to do with this mask - but how to sort it ?