Pierre Trudeau mispronounced "unPREcedented"... as "unPREEcedented"

When you are a musician as I am, you hear language differently. You hear the composition of the cadance, the rhythm and the pronunciation. Here Trudeau exposes himself as a mere reader who doesn't understand English and thus English reasoning when he says "un preeeee cedented". Other than that, a very good command of English pronunciation. I just can't understand how he could have made that error of making the short E and long E. I completely missed that back when this was live.