Specular flicker - Not enough samples

[Twist]

Hey. I see a lot of specular flickering in this animation. Is it because there isn't enough samples or is there another cause?

[hermit.crab]

Try the suggestions from this post.

[SonyBoy]

TBH this doesn't even necessarily look "wrong". Water definitely can produce specular hits like this with a moving POV when it's reflecting a bright light source such as the moon. So I'd say this is probably an artistic choice as much as anything.