There are a lot of fake RATs sold by Stateside sellers also. Just be careful and make sure you buy from a reputable dealer. I have an old AUS8 RAT, a fairly new AUS8 RAT and a new CF/D2 RAT. I'll pull them out tonight and see if I see any differences in blade profile. I do remember thinking that my oldest RAT had the best fit and finish...
This is true, there are some fake Rats, one of them is called Rat3, here is the difference:
In regard of the new D2 version, CF or - not, being with different blage geometry - I don't think so... I got all of them, in fact I have 2 D2 Rat1s and comparing them to the old Aus8 Rat 1 I at least, don't see any difference.
Again, another old picture, kind of angled, but still visible:
I can tell that the Ganzo's knock off and also the "Rat3" version do have different geometry, I hope the OP doesn't have one of those.
One thing to tell you have a knock off is the non-slanted standoffs, also the jimping is different and most of the Chinese knockoffs have G10 material for scales, not the nylon.
Hope the pictures will help.