The brothers have since been charged with high treason - but are unlikely to be jailed in Ukraine.
That is broadly the story of Kyiv's battle with collaborators. Those who commit more serious crimes - guiding attacks, leaking military information or organising sham referendums to legitimise occupying forces - are mostly tried in absentia.
Those facing less serious charges are often the ones who end up in the dock.
Under the Geneva Convention, occupying Russian forces have to allow and provide the means for people to continue living their lives.
Just as Tetyana Potapenko says she tried to do, when troops moved into Lyman in May 2022.
Her case is one of several we have uncovered across eastern Ukraine.
They include a school principal jailed for accepting a Russian curriculum - his defence, his lawyer says, was that although he had accepted Russian materials, he didn’t use them. And in the Kharkiv region, we heard about a sports stadium manager facing 12 years in prison for continuing to host matches while under occupation. His lawyer says he had only organised two friendly matches between local teams.
In the eyes of the United Nations (UN), these collaboration convictions breach international humanitarian law. A third of those handed down in Ukraine from the start of the war in February 2022 until the end of 2023 lacked a legal basis, it says.
“Crimes have been carried out on occupied territory, and people need to be held to account for the harm they’ve done to Ukraine - but we’ve also seen the law applied unfairly,” says Danielle Bell, the head of the UN's Human Rights Monitoring Mission in the country.
Ms Bell argues that the law doesn’t consider someone's motive, such as whether they are actively collaborating, or trying to earn an income, which they are legally allowed to do. She says everyone is criminalised under its vague wording.
“There are countless examples where people have acted under duress and performed functions to simply survive,” she says.
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