Visible crew/equipment: Just before Amanda shoots Lynn, a mini microphone can be seen on Amanda's neck. It is only visible for a few seconds then vanishes, so look quickly.
Visible crew/equipment: When Jeff is stuck to the fridge, you can see a cameraman's shadow on his shirt.
Visible crew/equipment: Just as Jeff and the judge walk out of the pig room, we see the judge walk through some plastic. When he walks through the camera is reflected on his back. (01:17:15)
Visible crew/equipment: There is one very quick shot when Lynn is asking Amanda for Ativan. In the one shot, look in the glass behind Lynn and see a boom arm. (00:37:50)
Visible crew/equipment: When Jigsaw is having a fit, there is one very quick shot after Lyne tells Amanda to back off, that a boom mic is visible above her head. (00:38:00)
Answer: It was too late for Adam to solve the game the way he was intended to- the key went down the drain, which Jigsaw actually didn't intend to happen. Adam's key was meant to be tied around his neck in such a way that neither him nor Lawrence would be able to see, and Adam would be allowed to go free and escape if he were to locate the key- which would only be possible if he looked at himself. The whole idea behind his puzzle was "looking at himself instead of others, for a change." The reason it went down the drain instead, was because of Amanda, who continuously made traps unsolvable. Instead of tying it around him like Jigsaw asked, she just tossed it on his chest, which defeated the whole purpose. Also, he was given a saw just as Lawrence was, as a much more violent plan B, another way he could save his own life.
That doesn't make sense because Jigsaw told Adam that the key is in the bathtub at the end of the movie.