The judge also cited other police testimony and character witnesses and an defense expert on police procedure who approved of Josey's conduct.
Dugan said the video alone was not enough to prove that Josey intended to harm Guzman: "This is not a social media contest, this is not trial by video."
Guzman, 40, the mother of three from Chester, and her attorney Enrique Latoison, were in court for the verdict.
Guzman, whose English-speaking ability is limited, was "very upset about what happened," said Latoison. "She felt disrespected. The whole Hispanic community was disrespected."
Latoison said he intends to filed a civil suit against Josey and also will contact the Civil Rights Division of the U.S. Justice Department to conduct an independent investigation of the incident.
"If this is what they can get away with on camera, imagine what goes on off camera," Latoison added.
When Dugan announced his verdict, the overflow crowd - nearly twice the 109-person capacity of the courtroom - erupted in cheers so loud that the judge asked them to exit: "This is still a court of law . . . I have 50 more cases to hear so please leave."
Outside the courtroom, Josey spent almost 15 minutes being embraced and congratulated by fellow officers and members of the Highway Patrol to which he was assigned.
Defense attorney Fortunato N. Perri Jr. said Dugan's ruling means that, under the Constitution ban on "double jeopardy," Josey cannot be retried.
Josey said he intended to seek reinstatement to the police department.
"It is what it is," Josey said of the video. "The media put it out there one way and kind of distorted it but it all worked out in the end."
District Attorney Seth Williams released a statement say he respected Dugan's verdict "but I disagree with it.
"Let's be clear, there were no winners on that day in September. While I believe Jonathan Josey was guilty of simple assault, this is not the time to dwell on that and I hope as a community we can move past this," Williams added.
Dugan, 52, a judge since 2007 and a decorated Army captain who served in Iraq and Afghanistan, conducted a three-hour nonjury trial on Feb. 12 but took the case under advisement, saying he would announce his verdict today.
Contact Joseph A. Slobodzian at 215-854-2985, firstname.lastname@example.org, or @joeslobo on Twitter.