The claim that "Ukraine killed 14,000 ethnic Russians who voted to leave Ukraine" is misleading. The number 14,000 comes from the total deaths in the Donbas war between 2014 and 2021. Those deaths included Ukrainian soldiers, Russian-backed separatists, and civilians. There is no evidence that all 14,000 were ethnic Russians or that they were all killed by Ukraine.
United Nations (OHCHR) Casualty Report
https://ukraine.un.org/sites/default/files/2022-02/Conflict-related%20civilian%20casualties%20as%20of%2031%20December%202021%20%28rev%2027%20January%202022%29%20corr%20EN_0.pdf
This report found about 14,200–14,400 total deaths in the Donbas conflict. It explains that the deaths included civilians, Ukrainian military members, and separatist fighters.
Potential Biases or Interests- United Nations: Generally considered neutral and focused on collecting data. Euromaidan Press: Pro-Ukraine news source, so it may present events from a Ukrainian perspective.
. What Evidence Supports the Claim? Around 14,000 people did die in the Donbas conflict before 2022. Some of those killed were Russian-speaking people living in eastern Ukraine.
What Evidence Undermines the Claim? The 14,000 deaths included soldiers and fighters from both sides, not just ethnic Russians. The UN does not say that Ukraine killed 14,000 ethnic Russians.
I could not find the original person who made the claim because it has been shared by many people online. Therefore, I was unable to contact them for a response.