The Britney Spears tape upon which Jason Alexander claims his ex-wife detailed the beating she took at the hands of Jason Trawick appears to be bogus.Alexander told Star that Spears' boyfriend beat her up, and she didn't call the cops because she feared a leak. He then leaked the tape to Radar Online.But a highly-respected audio expert tells TMZ that Jason Alexander's tape of Britney Spears "has been electronically stepped on," i.e. doctored. A lot.Britney and Jason in a show of public solidarity yesterday.Tom Owen of OWL Investigations is Chairman of the Audio Engineering Society Standards Committee of Forensic Audio. He says the tape was altered,...