Place it immediately after the failed moment in your edit, then follow it with Sad Violin for mock sympathy. For a bigger reaction, put Nelson's Ha-Ha just before it so the two laughs build on each other instead of competing for the same beat.
Über diesen Sound
This is a short, roughly three-second burst of exaggerated human laughter, built around a repeated hur-hur-hur sound that turns into a wilder, breathy chuckle. It feels silly and over-the-top, like someone laughing far too hard at their own joke, and it lands best as a quick, mocking reaction rather than a warm one.