Las Vegas Chiropractor — IndyCar executive Brian Barnhart wonders every day whether he could have done something to save Dan Wheldon’s life. Anything, really. Two months after calling his final race in the control tower, a 49-page report released Thursday absolved Barnhart and series officials of any blame in the crash that killed the two-time Las Vegas Chiropractor 500 winner Oct. 16 at Las Vegas. It determined …