Almost lost my long time rebel character (and main char at the time), Alisha Parker due to a complete misunderstanding.
The Bottlestreet Gang (main resistance faction) at the time thought I had snitched on them (even though I didn't) and decided to bring me into a slum apartment then knife me to death. However, after a large and dramatic roleplay session (with the BS members questioning themselves both IC and OOC, and a close call when one of the BS members decided to try to stab me anyway), I was hauled off to their secret base (the Bunker) at the time and partially healed up.
But the doctor didn't know what he was doing 100% so I was dying to infection. I told them to bring me to my friend then passed out and started going into shock.
I thought I was a goner since rebels back then were paranoid and killed you for just seeing you pass by a hidden base, let alone let you leave when you enter.
But the doctor decided to risk it and brought me out of the hidden base and brought me to my CMU friend, who operated on me and managed to save my life after a intense operation with the help of another doctor.
My character changed drastically after that; I had flashbacks of that moment ICly, was scared of knives and people to "come with her" as she thought it meant her death just like she almost died before (which would lead to her screaming and passing out from fear when a CP tells her to "come with me" to the Nexus a few weeks later but thats another story) and never EVER went to slums after that. She later became a hidden rebel / T6 loyalist but slowly got twisted by the system, and with the death of her friends who gave her hope, slowly became that which she wanted to destroy; a big cog in the Combine's well oiled machine.