Place it right after the failed moment in your edit, once the outcome is clear, then follow it with the Emotional Damage sound for a bigger reaction or the Game Show Buzzer for a harsher verdict. Let it close the failed moment, so the next clip can build on that failure.
About this sound
This is a short trombone accent that slides downward in a series of drawn-out wahs, ending on a low, flat note. It sounds deliberately deflated and a little ridiculous, like a brass band giving up in slow motion. The effect is instantly funny and a touch pitiful, turning a small mistake into a theatrical flop without a single word.