Lynch was formally charged with DUI on Wednesday in Alameda County, Calif. He registered a .08 blood-alcohol content, which the state considers legally intoxicated, when stopped by police early Saturday morning.
"There's a better than 50 percent chance he's .06 or .07 (in blood-alcohol content)," Lynch's attorney, Ivan Golde, told NFL.com. "Those tests have a margin of error. Science is there to prove it."
Golde raised issues with the two separate blood-alcohol tests administered to Lynch. The second test, given some 40 minutes later, registered a higher .10 blood-alcohol content on Lynch, Golde said.
The California Highway Patrol -- which also gave Lynch "multiple field sobriety tests," according to its report -- defended the results of the blood-alcohol tests.
"(Lynch) was arrested at the scene for being above the legal limit, which the chemical test later substantiated," CHP officer Melissa Kittell told NFL.com. "It's certainly possible for someone's blood-alcohol content to increase over time, depending when they started consuming."
Golde said the outcome will be "very positive" for Lynch, despite the DUI charge.
"The district attorney's office doesn't want to appear to be giving preferential treatment to anybody," Golde said.
Lynch doesn't have to be convicted of a crime to be suspended by the NFL, according to its player-conduct policy. He was suspended for three games in 2009 after pleading guilty to a misdemeanor gun charge.
Lynch, 26, signed a four-year, $31 million contract with the Seahawks in March. The deal includes $18 million in guaranteed money.