That is not correct. Key dialogue is missing from the above snippet. This is from Eve of Destruction:
Nick: I just saw Juliette
Trubel: What?
Nick: She's alive and you know it!
Trubel: No, Nick I---
Nick: Tell me the truth!
Trubel: I swear to God, I have no idea what happened to her!
Nick: But you knew she was alive.
Trubel: No, I mean not for sure.
Nick: She's either dead, or she isn't!
Trubel: All I know is that she was alive when Chavez took her, but I didn't know if she was gonna survive what they were gonna do to her.
What I said was correct. Trubel shot Juliette, thereby forcing Nick to believe she was dead. However, Trubel knew Juliette was alive at that point. She never ever confirmed to Nick what she knew until Nick confronted her.
Nick: I just saw Juliette
Trubel: What?
Nick: She's alive and you know it!
Trubel: No, Nick I---
Nick: Tell me the truth!
Trubel: I swear to God, I have no idea what happened to her!
Nick: But you knew she was alive.
Trubel: No, I mean not for sure.
Nick: She's either dead, or she isn't!
Trubel: All I know is that she was alive when Chavez took her, but I didn't know if she was gonna survive what they were gonna do to her.
What I said was correct. Trubel shot Juliette, thereby forcing Nick to believe she was dead. However, Trubel knew Juliette was alive at that point. She never ever confirmed to Nick what she knew until Nick confronted her.
The best way to frustrate a cyberbully is to ignore him.