As for the rest of what you said... I know over here a few courses and uni's use 3dsmax for teaching purposes in the uni labs, so its possible to be using max with out needing to buy it. If the person has bryce at home and they are familiar with it how to do the basics in it, I can definitely see why they would want to export bryce terrains to max simply for ease. Just my .03$ (inflation)

Dreams are just nightmares on prozac...
Digital WasteLanD