The best example (counter-example?) of this that I can think of is one of the realtime raytracing demos that came out circa 2000 when it was all the rage. I can't remember the name but basically after doing well in a compo the authors revealed that it was just a rasterizer running at low rez with some hacked reflections, which everyone had believed was super impressive because they thought it was raytracing and the deliberately low resolution made it look the part.