NEW YORK, N.Y. - A lawyer for a racecar driver who was killed when he was run over by Tony Stewart's car says legal claims by the NASCAR star in response to a lawsuit are "appalling."

Attorney Mark Lanier said Saturday in an email that Kevin Ward Jr. was killed last year as he walked on a dirt track in upstate New York even though Stewart is one of the world's best drivers.

The lawyer noted five other cars drove around Ward during a yellow caution flag before Stewart "revved his engine and ran him over." He called Stewart's legal papers in response to the lawsuit "appalling."

Ward's family sued Stewart this month for unspecified damages, accusing Stewart of gross negligence in the August 2014 accident at Canandaigua Motorsports Park.

Stewart's lawyer, Brian Gwitt, said in court papers Friday that Ward was impaired by marijuana and died because he exited his car during the race.

"Stewart was not aware that anyone had exited their vehicle," Gwitt wrote, adding that his client "did not see Ward, Jr. or anyone else walking on foot on the track until just prior to contact, and did not know the identity of the person walking on the track until afterward."

Lanier said Saturday that Stewart did not take a drug or blood test following the tragedy.

The lawsuit filed by Ward's parents notes Stewart's reputation for having a temper and claims Stewart deliberately veered toward Ward.

Evidence from the crash was presented to a grand jury in upstate New York, which declined to indict Stewart and called the incident "100 per cent an accident."