"Jesus said, 'If they are thirsty, give them water'," she yelled back.
"No, you know what?" he shouted. "These are not humans, you dumb frickin' broad! Hello!"
They continued arguing while the truck driver appeared to call the police.
"Film this!" Krajnc ordered to someone behind her. Then, she commenced tipping out her water bottle into the trailer. One of the pigs lapped it up.
Now, Krajnc has been charged with criminal mischief and faces jail time or a fine of up to US$5000 ($6830). She is a member of Toronto Pig Save, an animal rights group that regularly demonstrates outside Fearmans slaughterhouse and other meat processing plants. Videos on the group's YouTube channel show activists confronting truck drivers hauling cows, chickens and other pigs.
Krajnc's trial, which began this week in an Ontario court, has attracted the attention of animal rights activists, both in person - dozens of protesters gathered outside the courthouse this week, according to reports - and on social media, where supporters started the hashtag #StandWithAnita.
The case has also drawn angry responses online from those who feel activists like Krajnc are interfering with private property.
In court, truck driver Jeffrey Veldjesgraaf said he could not be sure Krajnc was actually giving the pigs water and was concerned the liquid would contaminate the livestock, according to CBC News. He told the court that he was transporting 190 pigs that day on a roughly 110km route, the Canadian station reported.
Veldjesgraaf said the pigs were not given any water on the truck - aside from what Krajnc poured into the trailer - but received water as soon as they reached the slaughterhouse, CBC reported.
Under questioning by Krajnc's defence lawyer, Veldjesgraaf said he told police that Krajnc and animal-activist groups had to be stopped because they were "messing with our livelihood", the station reported.
Eric Van Boekel, the farmer who owned the pigs in Veldjesgraaf's truck, testified on Thursday that he thinks the activists' regular truckside protests are a safety problem, the Toronto Star reported.
"One of my biggest fears - and it's not if it's going to happen, it's when it's going to happen - is one of the protesters has their arm in the slat, and the driver pulls away, they'll get [dragged] under the truck," Van Boekel said in court, according to the Star.
The activist has said her only crime was compassion and that she would do it again.
"I did what I did because I was just following the golden rule, like you'd treat others as you'd like to be treated," Krajnc told the Washington Post.
"If someone's thirsty, you give them water."
Krajnc said she started Toronto Pig Save in 2010 after witnessing trucks packed with pigs on their way to a Toronto slaughterhouse, which has since shut down, while walking her dog along Lake Shore Boulevard every day. "When someone is suffering, it's actually wrong to look away. We all have a duty to be present and try to help. In the history of the world, that's how social movements progress."
Krajnc said her defence lawyers will argue that she was not breaking the law but acting in the public good.
Krajnc originally faced up to a 10-year prison sentence, according to the Guardian.
The trial continues, with additional dates scheduled in October and November, Krajnc told the Post.
