... do you kick her in the kidneys, or do you help her up?
When the comrade beside you is captured by the enemy, do you curse her name and write her out of the movement, or do you rescue her if possible and aid her and keep solidarity with her if that's the best you can do?
If the enemy extracts information from the fallen or captured comrade, at what point do you determine that that comrade is a traitor rather than a victim? Do they have to waterboard her, pull out her fingernails, and show her a family member with a gun to his head? Or are there lesser coercion levels, including threats -- "we'll put you in a cage for 20 years;" "we'll abduct your children and put them in foster care;" "we'll seize your father's business" -- to which capitulation is an understandable, rather than treasonous, act?
In my view, we need to accept that the state is at war with us -- all of us, not just "movement people" -- and recognize that when we write off an actual or potential comrade because he or she was brutalized to the point of (quite possibly temporary) surrender, we are by definition adding one person to the state's ranks and removing one person from our own.
I'm not great at math, but that just doesn't seem like a very good idea to me.
Obviously there are information issues which may be less than completely transparent. Did the comrade capitulate under coercion, or actually change sides? Yeah, it's a universe of imperfect knowledge, isn't it? But let's work to realize our best aspirations instead of indulging our worst fears.