"I want to go back home," the accused said immediately after judgment. "I'm going to go home and find my life."
Neither the accused nor the complainant can be named due to a publication ban.
The complainant, who was not in court for today's verdict, remains HIV-negative.
In her judgment, Justice Lauri Ann Fenlon found the accused had unprotected sex with the complainant on three occasions.
She also found the accused deliberately lied about his HIV-positive status, and that his boyfriend would have not have agreed to have sex without a condom had he known the truth.
But Fenlon ruled the risk of transmission in this case — placed by expert testimony at 4 in 10,000 per sexual act for a total risk of 12 in 10,000 acts or 0.12 percent — did not constitute a sufficiently significant risk of bodily harm to convict.
"It's serious harm but less serious than it was when R v Cuerrier was reached," Fenlon ruled.
In 1998, the Supreme Court of Canada ruled in Cuerrier that knowingly exposing a sexual partner to HIV constitutes a prosecutable crime (aggravated sexual assault).
But things have changed since that decision was reached, Fenlon ruled.
"It's no longer the case that people infected with HIV will develop AIDS and die prematurely," she said.
"HIV, while still a deadly virus, can generally be treated and held in check."
That fact, coupled with the actual risk of transmission in this case (where the accused was exclusively a bottom), led Fenlon to conclude that the accused's failure to disclose his status did not expose the complainant to a risk of harm significant enough to warrant conviction.
"I have concluded that the Crown has failed to prove that the risk of HIV transmission here meets the standard of significant risk of serious bodily harm that must be met to turn what would otherwise be a consensual act into aggravated sexual assault," Fenlon ruled.
"The accused is therefore acquitted of the offence charged."
Fenlon said her judgment should not be taken as an endorsement of the accused's behaviour.
"He had a moral obligation to disclose his HIV-positive status to his partner so that the complainant could decide whether he wanted to take the risk of engaging in unprotected sexual activity with the accused, no matter how small that risk," she said.
"But not every immoral or reprehensible act engages the heavy hand of the law."
Defence counsel Jason Gratl welcomed the judge's decision.
"From a legal point of view, this case means that unprotected sex will not necessarily lead to a conviction even if the accused failed to disclose," Gratl said outside the courtroom.
"From a practical point of view, however, both disclosure and protected sex is the wise option to avoid prosecution altogether," he added.
Today's ruling suggests that "HIV is best understood as a chronic, manageable condition, rather than a fatal illness," Gratl said.
"But not all HIV-positive people should take comfort in this. The presence or absence of significant harm still has to be determined on a case-by-case basis," he cautioned.
Fenlon's decision is a sign that individual cases of risk, not HIV-positive status, will determine future convictions, Gratl said.
"This case builds on a growing body of case law that recognizes that there may be different transmission rates under different circumstances," he noted.
"It's almost impossible to know in advance the statistical risk of transmission attached to specific sexual activities subject to specific viral loads," he warned.
The best way for people to avoid being charged, Gratl emphasized, is to overestimate the risk of potential infection, disclose their status and use condoms.
In reaching her decision, Fenlon dismissed key parts of the accused's testimony as unreliable, pointing to his recollections of the one instance when he admitted he may have engaged in unprotected sex with the complainant on New Year's 2004.
"He filled in details to bolster his evidence," she said. "He said he didn't see the complainant's genitals when they had sex on New Year's Day and the accused also said he could not feel if a condom was being used but admitted that he guided the complainant's penis into him with his hand."
She went on to criticize the accused's previous assertion that the complainant would walk into the bathroom to dispose of the condom 99 percent of the time when they had sex.
"This is inconsistent with the testimony of the complainant ejaculating on the bed to complete the sexual encounter," she said.
She contrasted the accused's testimony with that of the former roommate who she described as a truthful witness, and the complainant, who she felt was generally truthful and straightforward.
"In my view, this court case does not change the balance of responsibility between HIV-positive and HIV-negative persons," Gratl told Xtra.
"Prudent HIV-negative persons who are sexually active must continue to protect themselves by insisting that condoms be worn," he said.
"From a medical point of view, HIV-positive individuals, whether top or bottom, should continue to protect their partners by insisting that condoms be worn," he added.
"What this case really stands for is the proposition that unprotected sex in relation to which the HIV-positive partner has not disclosed their HIV status, is not necessarily in all cases criminal," Gratl said.
"In many cases it will continue to be criminal," he added. "In all cases it will continue to be unwise."
When asked if the Crown plans to appeal, Crown Counsel Brendan McCabe said he had no comment.