Highly doubt 1 redirect is the sole reason.
What did they tell you the reason was?
If they penalize you for links/redirects, they tell you, they don't need excuses.
Why do you think they say the site was hacked with spam?
My site is clean and OK on Bing.
Looks like they're not going to tolerate any 301 that's not relevant.
Keywords rank on page 1 and 2 on Bing .
Even my site name don't show on Google when I search.
I did a search online using an internet tool to check the site just before I got the message. So maybe these online checkers are sending info to Google?
Or maybe I'm being paranoid but something's happened.