Accidental Acts of Kindness
I can't imagine how we can be kind accidentally. Our kindness may have unintentional consequences, such as when we are kind to the checker at the grocery store. The next person in line who witnesses our actions may feel better about the world. But we were intentionally kind to the checker in the first place.
Haphazard Acts of Kindness
This brings up images of someone stumbling around and spilling splashes of kindness paint on passersby, creating a Jackson Pollock-type world.