No one has shown any evidence that Microsoft has directly copied Google's search index, or even violated the directives in google.com's robots.txt file.

What Microsoft apparently has done is to infer relationships from Gooogle SRPs to various sites by way of information gathered through the Bing toolbar (and possibly other documented and user opt-in channels w/in IE). Using toolbar collected signals is well-established practice -- that's how Google obtains information regarding site performance.