Place it at the peak of a failed defence, just after the flank is revealed, then follow it with Enemy Spotted to underline who was missed and keep the focus on the teammate's mistake.
關於此聲音
The clip is a strained voice shouting the name Kapkan three times in quick succession, lasting just over three seconds. It sounds panicked and exasperated, like a warning shouted a moment too late when danger is already beside you. It comes from Virefly's Rainbow Six Siege stream, recorded as two enemies rushed the player using Clash while the teammate stood right next to them.