Except, you run that check to make sure your not running afoul of someone's trademark restrictions/ using a logo associated with an existing brand. (Which, unless I am missing something here, they are not.). They should have run it, but just because they found your result doesn't mean they had to scrap something they (allegedly) did themselves.

If they came up with it independently(a very legitimate question given the similarity of the --- very nice by the way --- logo, but one they seem to have evidence for) then there seems to be no moral problem or even a legal issue.

You're basically claiming "I thought of it first, there for it's mine" which is both legally wrong in the US for copyright(independent creation is a defense) and morally bullshit in the same way that Amazon's one click ordering patent is.