In Scenario 1, my first thought is.. "Why are the programmers competing, they should be working together". But, I realize that isn't the point. I like programmer B's solution right up to the point he started cutting out the comments. If he's trying to pass off somebody else's work as his own, then I would say yes, he is cheating just as Child B is cheating.

On the other hand if neither programmer B or child B attempt to pass off the work they discovered at completely their own, then I would argue that neither of them cheated, and did actually show initiative.

Finally, if the parameters for task X state that the work has to be 100% of their own doing, then you could argue that neither programmer B nor child B actually achieved the requirements. I still don't think that's cheating, its just failing to do what you had to do...