It's not really any of my business, since I didn't submit to this anthology, but if consulting a lawyer is necessary, wouldn't it just be better to go with another image? I know that one is eye-catching, but is it worth the hassle?
In looking over depositphotos license terms, I'm a little concerned that there is no reference to editorial images whatsoever. Yes, the site has an editorial photo section, but no explanation of any specialized restrictions that may be in effect, at least not that I can find. By contrast, Shutterstock slaps you in the face with its list of restrictions on editorial images at every turn. I find the omission a little concerning.
If you do decide to go with the existing cover, be sure to ask the attorney about possible claims arising from the underlying photo which this image clearly evokes. Normally, I would think any suit arising from that kind of problem would strike the creator of the image rather than you, but the indemnification language in the user agreement might muddy the water. Then again, maybe the weight of litigation would hit the cover designer. It would certainly be a question worth clarifying, though.
BTW, the fact that an image is widespread doesn't mean it's fair game.