There were Neonazis in the militias fighting on the Ukrainian side.
At this point in time, is safe to say that neo-nazism in Ukraine isn't a rare ocurrence or a one-off.
They have multiple openly neo-nazi units within their armed forces, they openly glorify Stepan Bandera as a hero and deny his documented involvement in the Holocaust; they even go as far as financing monuments to the SS in the West and inside Ukraine. Even several members of the government were neonazis.
Even if the majority of the western Ukrainians aren't neo-nazis themselves, their tolerance for nazis makes them complicit at the very least.