少し前のことになるが、私は或る評論家がインターネットのウェブサイト上に。。。
Generally, when I see ことになる, it means something along the lines of "it is/was decided". But here, that meaning doesn't seem to apply. What is the nuance being communicated here (if it helps, this is the first sentence of an essay)? Why not use 少し前のことですが ?