Asking what tool was used to make an image is, often, like asking which text editor was used to write a program. Unless whatever tool they used had some unique capabilities to make it easy to create images in the same style, it's irrelevant (because someone skilled enough to do it with one tool could do it with another).
Ok, so you're saying that you wouldn't have any problem manipulating some complicated photos (changing backgrounds, masking out certain elements, changing color levels, creating alpha mask, adding drop shadows to text, touching up a person's face, blending several layers together so that the layer below comes through to the layer above, etc, etc) in Microsoft Paint instead of using Photoshop?
After all, they're both just "text editors" as per your example.
