The evening star pattern can absolutely fail, especially in sideways markets, without confirmation, or during strong macro uptrends. The Evening Star candle must appear after a clear uptrend to be valid. If it shows up during sideways movement or after a downtrend, it can give false signals.
If the fourth candle reverses and closes above the second candle's high, the pattern failed immediately and the reversal signal was false.
The pattern's success rate is around 55-68%, depending on asset class, setup, and market environment.
Confirm with volume, RSI divergence, and resistance confluence before shorting.