The lawn mower is operating within the laws that constraints it (laws of physics in this case) and not a greater sense of morality.

Lessons:

- The only way to constrain what the lawnmower does, is make sure what do desire is enforced by law (physics)

- A reminder, the lawnmower will chop your hand off and think nothing of it

- The lawnmower is not "evil" but if the laws that constrain it allow for evil behavior, it may do "evil" things.