Here's what happens to me.
Let's say I win nothing on the first spin, and I win something on the second spin. However, since it looks like I won't be winning anything in the third spin, I click Ok before the third spin is over...and I lose the card I won in the second spin.
I'm 99,9% sure that this is incorrect.
I have been canceling 3rd spin since day 2 of my Elements career and I've never experienced this, so unless it's a very recent change, it's false alarm.
Yeah I'm pretty sure that once the card pops up and the third spin starts you retain the second card.