I figured this out: it's not a bot it's "Google WAP Proxy/1.0"

User agent: Nokia6610I/1.0 (4.10) Profile/MIDP-1.0 Configuration/CLDC-1.0 (Google WAP Proxy/1.0)

I know the reason I was banned and I have already cleaned the site. I just wonder why Google doesn't send warnings or something, they just manually delete your domain and all pages in it from their index and cause a lot of problems for webmasters. In my case the domain had several websites, most of them 100% clean with no SEO of any kind.

My top positions have been taken by domains that use doorway pages with javascript redirects. It's a bit unfair that some get manually banned for something others in the same business continue on doing for months, maybe years to come.