My recent employment adventure turned me cynical. My then-soon-to-be boss seemed great during the interview. He was technical, his questions were interesting and deep and the team seemed happy. Turns out he was a complete sociopath who made everyone's life living hell. The unhappy weren't invited to the interview.
The first clue from the second day at drinks should've been, "I voted no in hiring you, but [his boss/my previous company's CTO] convinced me to change my mind." in front of the other senior admin. Kinda downhill from there.
What makes these situations so difficult is that leaving a job early has such a strong negative effect on your future work prospects. Even worse, being unhappy at a job affects your work prospects, too. There really isn't a win in those situations.