Just in case u didn't find the time to kook at it. The Black sea fleet was split between Russia and Ukraine but because of the history of the fleet itself they kept very close ties and unless they speak out it is difficult to be absolutely sure but if they thought possible to receive orders to engage the Russian navy from the new gov in Kiev, well resign was their best option to escape a situation every bit of their soul rejects. Can get u more more details if u need it
At the same time, to dramatize as much as possible and exacerbate the possibility of an armed conflict with Russia can be the solution the gov in Kiev has picked to force out of the Ukrainian state and armed forces apparatus anybody deemed to have a loyalty issue, m I making myself clear?