Backtest trade hit stoploss even though price never went that far

 
Wilson Wong:

Is it a glitch? But i can consistently reproduce it.

You are wrong. The price went to your stoploss. Not the BID price (chart is contains bid prices) but the ASK price.
 
Petr Nosek:
You are wrong. The price went to your stoploss. Not the BID price (chart is contains bid prices) but the ASK price.
Thanks for pointing it out.