This is a good bit of journalism. I wonder, however, if it might be enhanced were you to take a stance toward the subject matter. At the very least, I think it could be helped by rearranging the elements in such a way as to create the natural arc that seems to be inherent in the material.

I would suggest moving from the particular to the general. There are many different elements here and at times there seems to be something of a scattershot approach. Here's a suggested arrangement:

Begin with your encounter on the bus. This your personal connection and if you start by telling us why you were impressed with this poet, you will have lead with material that cannot be argued against or disputed: you felt the way you felt, end of story. It's a trick, maybe, but a good one. We begin by accepting what you say at face value. After that, the facts themselves create the tension.

Next, the material on why this poet was famous. Here you might give a little background on the poetry establishment in general, not just in Africa but globally, and the role that contests and awards play in creating a poet's reputation.

At some point a question needs to be raised explicitly. You dance around it but it is actually the missing heart of your piece. The question is this: Many have accused the poetry industry (much like the music industry or the art industry) of being little concerned with poems themselves and much more about publicity, connections and politics. Is the a fair assumption? However you answer that question, you would have a driving theme beneath the surface events that will focus yours and the reader's attention.

Another related question: this poet was at it for quite some time. Then, when one media source found problems, suddenly, within days it seems from reading the text, the dominoes fell and all was revealed. If it was that easy to find him out, why had no one (including the actual poets who were plagiarized) manage to do so before? Was this a case of willful ignorance? again, the questions lead back to the poetry establishment. In this light, Redscar becomes something of a Maguffin, the inert mass a the center, around which the actual story coalesces.

This case raises many disturbing questions. You've suggested that the questions exist, but an effort to answer them would make this a much stronger piece.