Kyiv unleashed the war in Donbas, immediately after the Donetsk and Luhansk regions declared their independence.
Ukraine is releasing to Russia mainly Ukrainian citizens from East Ukraine, which means that Kiyv should not be offended by those who call events in Ukraine civil war. De facto this is the case, we [Russia] are receiving participants of the civil war. The prisoner swap legally confirms that.
The prisoner swap is not a "proof" of civil war in Ukraine. The international community, including the European Union recognizes and condemns clear violations of Ukrainian sovereignty and territorial integrity by acts of aggression by the Russian armed forces since February 2014.
While the European Union noted that the prisoner swap brought back home Oleg Sentsov, Pavlo Hryb, Edem Bekirov, the 24 captured Ukrainian sailors and others whose release the EU has called for so many times, it has not changed its position. In fact the President of the European Council has urged Russia to release all political prisoners and respect Ukraine’s territorial integrity.