I had an old piece of art removed because it was thought to have an erect penis in it. Based on the time it was submitted, it had to be one that I'd hidden with the intent to remove, so I don't really care (although I don't think I've ever submitted art with a penis visible, erect or otherwise). However, I wasn't told the name of the piece, nor given any way I could download it (or upload a corrected one preserving the text, which is for me often as important as the image. That all strikes me as a poor policy.
DA, like any community, needs rules, and enforcing them helps me get my art, with the occasional mature age, seen. I'm truly happy about that. However, when users' art is removed without them having any chance to contest the challenge (which may have been erroneous), to submit an updated version that meets standards, or to just get the offering piece to preserve it for themselves is needlessly antagonistic.
Instead of deleting the art immediately, so the take-down note leads to a 404 page, they could set the art to only the artist can see it, giving them a period of time (30 days?) to review and act on the note. If they felt the notice was wrong ("That's not a penis! It's a shadow—ha, hilarious!"), make a replacement version that meets TOS (and preserves any comments on the piece when they replace it), or just save it for their own use.