Does this sentence make sense?

Hi, I have an assignment due tomorrow (an upper year History course in university), and I have to analyze a book I was assigned. One of the parts is to make note of any spelling or grammatical errors I find. I think I have found such a mistake but I want to make sure. The sentence:

The second incident involved one man, Alex Sandula, a mechanic who, unawares, picked up a “rabbit,” a piece of fuel rod that having passed through the reactor neutron flux then ricocheted off the shielding and onto the floor.

My immediate reaction was that "unawares" was mistaken for "unaware". I looked up unawares and saw it meant unsuspectingly...

But the second part of the sentence looks like it's missing something. A verb maybe? Flux can apparently be a verb: to melt, but seeing as the sentence is past tense, shouldn't fluxed be used instead?

Thanks in advance!