People coming to unstable states like US or Ukraine, balancing on the edge of government collapse, should expect such things to happen with pretty high probability. I really can't see why this could be surprising at all.
Actually Ukraine is the stable escape strategy for conferences which should have been held in Russia. Latia is also quite popular, but Ukraine is the usual target to escape Russia's strange visa handling.
I wonder what will be the escape country for the US situation. Canada or Mexico.