Margaret - the way you confidently state things that just aren't true is annoying.
If you look even at a basic source - like Wikipedia, for instance - you'll find that the Weinsteins were heavily involved from the get-go: this was a finance-and-distribution deal between the Weinstein Company, Tarantino and Universal. This is absolutely common, public knowledge. Also, 'executive producer' is not a title for someone who does nothing, but the name given to the person who essentially oversees the project management of the film from an accounting perspective, usually someone with a financial stake.
"Tarantino teamed with The Weinstein Company to prepare what he planned to be his film for production. In July 2008, Tarantino and executive producers Harvey and Bob Weinstein set up an accelerated production schedule to be completed for release at the Cannes Film Festival in 2009, where the film would compete for the Palme d'Or. The Weinstein Company co-financed the film and distributed it in the United States, and signed a deal with Universal Pictures to finance the rest of the film and distribute it internationally."
en.wikipedia.org/wiki/Inglourious_Basterds
"For good reason. Brothers Bob and Harvey Weinstein, who co-financed the $70 million movie with General Electric -owned Universal, need more than buzz from Inglourious Basterds; they need it to be a hit." - www.forbes.com/2009/07/31/weinstein-movies-hollywood-business-entertainment-weinsteins.html
Band a Parte is Tarantino's production company. Named for his love of Godard. Studio Babelsberg are a German company with a long pedigree of world class filmmaking. These guys would have done the more day-to-day work of production, but the Weinsteins kept a close eye on production for this one - not least because their company was having a torrid time of it financially and they were really struggling.