Source: https://physics.aps.org/articles/v10/66
This publication[1] says neutrinos, but the article it references says antineutrinos[2].
That explains my misunderstanding.
1 https://www.energy.gov/science/np/articles/detecting-neutrin...
2. https://www.osti.gov/pages/biblio/1959810-evidence-antineutr...