I know this will sound crazy, but honestly I think this was the worst game Carson Palmer had, rather than that 4 INT game 2 weeks ago.
I say this because in that game, he had probably a total of 6 actual bad passes and I think he got over 60-65% accuracy. Today he just looked BAD. 17-44, 12-25 I think at half-time. There were drops, but most of the missed passes were ones too high (including one about 15 yards too long later on), just off target by several yards or a WR by the sideline, thrown out of bounds not close enough for a shot to catch it.
You can go 50% accuracy in a game because of defense, drops, etc. There were drops, but the non-completions were simply bad passes. I think that, coupled with the fact we got 3 points on 4 turnovers, is the big reason the Bengals lost.
You can look at the penalties and that had an effect and of course the Bengals running game didn't do anything, but then it never does well against the Steelers and you come back to the passing game along with turnovers. If you win the turnover battle by a big margin, got great field position and drove the ball at times, well, but only get 2 touchdowns, very bad.
Next game for the Bengals is at home against the recently-good Rams, 1 PM next Sunday.