The impact can be seen at about 8 seconds into the video above, on the upper left side of the planet in this view.
Sky & Telescope reports:
“Not just one but two veteran planetary imagers caught the shots of a lifetime on June 3rd, when they both videorecorded a tiny, brilliant flare on Jupiter swelling and fading at 20:31 Universal Time. The flare brightened and faded in about two seconds. Its progress is recorded on many frames of each video.
The flare may have looked small from Earth, but it must have been titanic to be visible from Jupiter’s distance — and on Jupiter’s daylit side, no less. It was presumably the impact of a small asteroid or comet nucleus.”