Deciding when to remove males is a balance between certainty and tent room, since waiting for an unmistakable sac costs you a week of light and water on plants you will bin. Most growers cull at the first clear preflower rather than waiting for confirmation. Discussion of how early is too early to pull a suspected male sits at https://breederregularseeds.com. Getting it wrong occasionally and losing a female is the price of moving fast.
