Some actors walk off, most are fucked with during the entire time. For instance, the a/c is always really really high, chairs are wobbly, and shit's stinky sometimes. In the earlier parts of the seasons the actors were clued in but they stopped doing that and started doing things without a script.
Anyway, sometimes it's hard to make 45 minutes to 1 hour of torture into 4 decent episodes worth of material. A good few minutes is best.