To me, it's actually the lack of any indication that work is happening that gives of cheating vibes. If someone sits their glassy-eyed for twenty seconds, and then starts speaking in complete sentences, it is going to come across as though they are reading. Not to mention that people's intonation is often different if they aren't thinking up what to say.
If you do get stuck, you can avoid ambiguity by sharing some meta-commentary on what you are thinking and why. "I know that library uses X, but I'm not sure if it can do Y and I'm trying to think if I could work around that... okay, so what I would do is..." Something like that, so that the interviewer knows where your ideas are coming from.
To me, it's actually the lack of any indication that work is happening that gives of cheating vibes. If someone sits their glassy-eyed for twenty seconds, and then starts speaking in complete sentences, it is going to come across as though they are reading. Not to mention that people's intonation is often different if they aren't thinking up what to say.
If you do get stuck, you can avoid ambiguity by sharing some meta-commentary on what you are thinking and why. "I know that library uses X, but I'm not sure if it can do Y and I'm trying to think if I could work around that... okay, so what I would do is..." Something like that, so that the interviewer knows where your ideas are coming from.