Notty, the most this proves - even if you accept it at face value - is that a single guy fired at the riot police and he claims he did that only to scare them. Given the amount of violence that had already occurred in a very violent and longstanding confrontation, a small faction of the protestors may well have wanted some payback and escalated the conflict as described.
But the Putin Line on all of this is that all or a majority of the shooting was perpetrated by the CIA and Ukrainian neo-Nazis and the Berkut was then blamed to validate the overthrow of Yanukovych. Your source does not suggest anything remotely like this scenario.