I spent 4 Million + on spins, and in some instances I've noticed the rolling animation would not be going at the same pace each time? It would be fast, going through all rarities. Then, it'd be like it automatically selects common or something from the left column.
#Strange Wizard Traits
tough knot
wanton stump
Pretty sure that's just a design choice. The game automatically knows what you will get by the second you hit that spin button, so the animation doesn't correlate.