Thomas was acquitted of two counts of perjury. "I already had one career taken away from me," she yelled. "Look me in the eye. You can't do it."
Thomas then turned to a prosecutor and shouted, "Look me in the eye .... You like to destroy people's lives."
Prosecutors had no comment after they left the courtroom.
Thomas was banned from cycling for life in August 2002 after the performance-enhancing drug Norbolethone was detected in her urine. The drug, once an obscure steroid used in human tests in the 1960s, was rediscovered by chemist Patrick Arnold, who supplied the Burlingame-based BALCO with undetectable performance-enhancing drugs. He pleaded guilty in 2006 to drug charges.
Thomas had told the grand jury that she didn't know Arnold and never received any steroids from him.
During the cyclist's seven day trial, jurors heard testimony that ranged from arcane discussions of human hormone science to detailed and deeply personal descriptions of how Thomas' body apparently changed after she took the substances.
Dr. Margaret Wierman, an endocrinologist at the University of Colorado, testified that when she examined Thomas in 2000, she observed masculine body features.
"My recollection was that when I examined her, she had specific signs of evidence of a full beard" and other features, including male-pattern balding, diminished breasts and unusual patterns of hair on her chest and arms, Wierman said.
She also said she observed Thomas' deep voice, and wondered whether that would reverse itself later.
Arnold testified at the trial last week that he supplied Thomas with steroids.
Baseball star Barry Bonds also is charged with perjury for allegedly lying to the same grand jury about never knowingly using performance-enhancing drugs.
Legal experts said Thomas' trial offered Bonds' lawyers a preview of what kind of evidence the slugger will face if his case goes to trial as expected. Two of Bonds' attorneys, for instance, watched the government's lead steroids investigator testify.
The investigator, IRS agent Jeff Novitzky, is expected to play a starring role for the government during Bonds' trial.