The numeric spinner issue is much less severe. Calculators are often used in higher speed for a lot of calculations. That bug makes the calculator unusable for many people. The spinner is not used that often and waiting for an extra second there doesn't add up as much time.
That's assuming you know about it and all you have to lose is time.
Since it's an alarm, as another comment has exemplified, you may actually miss an important event in your life because you didn't know to wait for an animation to complete before saving your alarm.
I would say that this is severe given the potential outcome.
Similarly, the calculator bug is more of an annoyance for people who know about it, which is already bad, but the problem really manifests to those who do not know about it and may end up, say, wiring the wrong amount in a money transfer because their phone calculator didn't finish the animation in time to register actual key presses.
This is UI making the outcome of user operations actually wrong, not just laggy.
