Candlesticks are like any other tools. They have a high probability of predicting the future price but two people may see two different patterns and draw opposite conclusions..
I get out of a losing trade with a 5% loss. If the trend reversal does happen, just get back in. There are so many opportunities every day. Why stay with a losing position. By being stubborn like this, your friend will eventually lose. The worst thing that can happen is getting a margin call...