The 302 redirect issue, also known as Page Hijacking, has been an issue for a long time now. A thread at WebmasterWorld is 46 pages long, almost 700 posts, plus many other threads on this topic can be found at WebmasterWorld as well as all the other SEM forums. A well respected forum participant named Claus, has created a resource on this topic named Page Hijack: The 302 Exploit, Redirects and Google, here is the absract:
An explanation of the page hijack exploit using 302 server redirects. This exploit allows any webmaster to have his own "virtual pages" rank for terms that pages belonging to another webmaster used to rank for. Successfully employed, this technique will allow the offending webmaster ("the hijacker") to displace the pages of the "target" in the Search Engine Results Pages ("SERPS"), and hence (a) cause search engine traffic to the target website to vanish, and/or (b) further redirect traffic to any other page of choice.