The teen was rushed to Children's Hospital of Philadelphia suffering from bleeding on the brain, a fractured pelvis, and broken leg. He missed three months of school.
The jury of seven men and five women deliberated more than four hours before coming to a conclusion.
"This defendant reeks of dishonor, cowardice, and shameful behavior," prosecutor Joseph McGettigan said after the verdict. He said he was at a loss to explain the jury's decision to find that Vantrieste did not suffer a serious bodily injury.
McGettigan asked that Donohue be remanded to the county jail until his sentencing.
When Donohue heard Judge John L. Braxton raise his bail to $100,000 cash over the objections of defense attorney Mark Much, he took off his ring, emptied his pockets, and put his cellphone on the table. He was then led away in handcuffs by sheriffs.
The case had several twists and turns.
Donohue did not turn himself in until days after the crash, and a forensic toxicologist, a key witness for the prosecution, was not allowed to testify to the blood-alcohol level of someone who had Donohue's build who had consumed a substantial amount of alcohol.
A former waitress at the bar testified that Donohue ran up a bar tab of $120 that night. None of the witnesses, however, including eight former or current members of the District Attorney's Office who were at the bar, testified that Donohue appeared impaired.
After the prosecution rested its case, Braxton acquitted Donohue of the more serious charges, including aggravated assault and driving under the influence. A simple assault charge was later dropped, which left Donohue facing only leaving the scene of the accident and more minor charges.
In closing arguments on Monday, Much noted that the prosecution had not called a trauma doctor as a witness to prove that Vantrieste had suffered serious bodily injury. Instead, the prosecution relied on the testimony of the victim and his mother, who both had an interest in the outcome of the case, he said.
After the verdict was announced, Vantrieste said he thought the conclusion was wrong. The defendant knew the laws and should have followed them, he said.
"If you are going to hit some kid, run," said Vantrieste when asked what he learned from the experience. "You'll get away with it."
Contact Mari A. Schaefer at 610-892-9149, firstname.lastname@example.org or @MariSchaefer on Twitter.