I would not call correctly deducing that the smoke is OK from the correct perception that the other people in the room are confident that it is OK a bias. The lower rates with the confederates may indicate people have some ability to tell the difference between another person actually believing that nothing is wrong and the other person remaining calm while still considering whether something is wrong. Of course, it would be interesting to know whether this ability comes from talking with the other person or merely observing them.
Generally, when a psychology experiment allows its subjects to find clues about its real purpose, you have to consider the possibility that the results represent the subjects seeing through the experiment.
I would not call correctly deducing that the smoke is OK from the correct perception that the other people in the room are confident that it is OK a bias. The lower rates with the confederates may indicate people have some ability to tell the difference between another person actually believing that nothing is wrong and the other person remaining calm while still considering whether something is wrong. Of course, it would be interesting to know whether this ability comes from talking with the other person or merely observing them.
Generally, when a psychology experiment allows its subjects to find clues about its real purpose, you have to consider the possibility that the results represent the subjects seeing through the experiment.