They have to use an RNG that has each prize associated to certain numbers. Otherwise, if they are selected as soon as the button is hit, then the animation is an intentional misrepresentation of gambling. 2021 they and their parent company, Aristocrat Leisure, were sued for $115m for rigging gambling in games and intentional misrepresentation of gambling games. What's really interesting is if they're using a PRNG (pseudo random number generator) which is also illegal in gambling as, despite looking random, it isn't. Also, if it were as simple as you say, why not just send the data as proof instead of refusing? Now, I am not claiming I know exactly what's going on here and you may very well be correct. I am simply saying what my legal understanding is from the courses I've taken and my friends input that is a programmer.