I think you meant "epitome," meaning the ultimate. "Epiphany" is like a revelation.
See, I took it as "epiphany of stupid," meaning that the writer had never before realized how stupid someone could be. Compare to an epiphany of holiness, the birth of Jesus, and you can imagine what the epiphany of stupid would be in contrast.
Nope,
Epiphany was the intended word - it was a thunbderstroke of a revelation of how stupid he really is...