I'm no pro, but I can write poetry pretty well and as far as my take is, there aren't really any grammar or punctuation rules in poetry. Punctuation is supposed to help with the meter and flow of the work; the stuff about setting off prepositional phrases and so on is only for prose, really. I rarely use punctuation in my own poetry. It's easier for me to read, but it can be difficult for others to get the right cadence down.
My own sense of rhythm would have Oleg's work read like this:
Just around midnight, she called 911
But by 12:06 the fighting was done
No time to wait for police to arrive
So she used her trusty rifle to help keep alive