[4] Barr has often worked as an expert witness, including testifying in the Toyota Sudden Unintended Acceleration litigation.
There are several technical articles that discuss the various electronic throttle control defects he testified were linked to unintended acceleration that caused deaths in Toyota Camry vehicles.
[9] He has also worked as a testifying expert witness in other high-profile litigation involving software, such as SmartPhone Technologies vs Apple and in a copyright dispute about EA's early Madden Football video game source code.
[10] Barr began his career working as an embedded programmer at Hughes Network Systems, where he wrote software for products including the first-generation Hughes-branded DirecTV receiver, which sold in the millions of units.
[9] From 2000 to 2002, he taught ENEE 447 Operating Systems Theory as an adjunct professor in the same Department of Electrical and Computer Engineering.