Lawyers for a man accused of assaulting a woman at a Trump campaign rally last year have said he acted at the urging of the candidate, complicating the president’s argument in court that he stands immune to civil lawsuits.

Alvin Bamberger was recorded in a video last March pushing a woman, Kashiya Nwanguma, at a pro-Trump rally in Louisville, Kentucky. During the altercation, Trump shouted “get out” and “get ‘em out of here!”

A few weeks later, Nwaguma and two other protesters sued Trump, Bamberger and a third man, the white nationalist Matthew Heimbach. Last month a judge ruled that the protesters have sufficient claims to move forward with their court cases, which claim that they were assaulted at Trump’s incitement.

On Friday, Bamberger’s attorneys denied that he assaulted Nwanguma, saying in a new court filing that he “admits only that he touched a woman”.

But the attorneys also made a claim against the president and his campaign, observing that throughout the 2016 election Trump repeatedly urged supporters to expel protesters, and once hinted he would pay any legal fees of those who did.

“Bamberger had no prior intention to act has he did,” the attorneys wrote. “Bamberger would not have acted as he did without Trump and/or Trump campaign’s specific urging and inspiration.

“To the extent that Bamberger acted, he did so in response to – and inspired by – Trump and/or Trump campaign’s urging to remove the protesters.”

The lawyers add that if Bamberg is found liable, Trump or his campaign should be held equally to blame “because Trump and/or Trump campaign urged and inspired Bamberger to act as he did”.

Also on Friday, the president’s lawyers argued that Trump and his campaign “lack sufficient information” about most of the allegations “and therefore deny them”. The attorneys also said Trump’s “get them out of here” remark was not directed at the crowd.

Among 15 defenses, Trump’s attorneys said he “is immune from suit because he is president of the United States”; that the protesters waived their claims by obtaining tickets to the rally; and that the protesters “suffered no actual injury” while also being “responsible for their own injuries”.

“Plaintiffs’ claims are barred by their unclean hands,” the lawyers concluded.

Trump’s attorneys also requested a jury trial. The protesters are seeking an unknown amount in damages.

Bamberger, Heimbach and a third man, Joseph Pryor, were charged last summer with misdemeanor harassment by Louisville police.

A member of a Korean war veterans association, Bamberger, 75, last year wrote a letter to a veterans’ association that expressed regret for his actions at the rally.

“Trump kept saying ‘get them out, get them out’ and people in the crowd began pushing and shoving the protesters,” he wrote. “I was caught up in the frenzy. I physically pushed a young woman down the aisle toward the exit, an action I sincerely regret.”

Bamberger said he himself was “knocked down and hurt” and stressed that he did not belong to “a hate group like [white supremacists] and I don’t condone any of their actions”.

In a blogpost for his white nationalist group, the Traditionalist Youth Network, Heimbach also admitted a role. Video of the rally, Heimbach wrote, “features yours truly helping the crowd drive out one of the women who had been pushing, shoving, barking, and screaming at the attendees for the better part of an hour”.

He added: “Taken out of context, the elderly veteran, several others in the crowd, and I appear to be roughing up the woman because she’s black.”