We felt that we could tell the difference in reflection between moissanite and diamond. However we did go with a lab grown diamond which is 30%-60% of the price and ethically produced.
Did you blind yourself or did you know going in which was which? Did you separate so that each of your opinions would not influence the other?
Of course maybe there is a noticable difference but often people see/taste/hear/smell/feel something that's not there if they already know which is A and which is B.
The tells are obvious and easy to spot once you know what you're looking for. The moissanite has more fire than the diamond of the same shape and cut, and the angle of the point is shallower. The angle is particularly the easiest way to tell if the setting allows you to see it. I guess in the grandparent's post the point was hidden from the jeweler.
I don't think any of this stuff really matters, btw, just get what looks good to you.
The angle in the facets of the point has to be right to keep the light bouncing back out through the face and not right out the bottom, and it's determined by the physical properties of the material. For silicon carbide the index of refraction is higher, so the light will be bent more sharply when it enters, resulting in greater separation of white light into color components ("fire") and necessitating shallower angles in the point to maximize internal reflection
I've done a single-blind test and could tell, but to be completely honest I don't think they're similar enough that you need to set up an experiment. Go to a jewelry store near you; you'll be able to tell the difference quickly if you try.
