Jimmy Smits did not comment on his Season 6 departure from his role as Det. Bobby Simone, only saying "it was time to do something else" and agreeing to a five-episode story arc to properly let the character say goodbye. Speculation ran amok as to what was going on, but years later Smits told the whole story: he found series creator David Milch's creative and writing style so erratic and exhausting that he needed to take a break from both the show and acting altogether for a little while.
The trivia items below may give away important plot points.
In a special program prior to season ten, Jimmy Smits recalls the time during his last season on the show. The TV scripts were becoming delayed and late prior to the shooting. In some cases, the script did not show up until the day of the shooting. Smits said that he could not perform in the series without being able to rehearse any of the scripts and then asked to be written off the show. In season six, his character was written off by having a health issue.
First episode with no crime being committed and nobody in the squad actively investigating any cases. Detective Sipowicz Dennis Franz is trying to help out his ex-wife Debra Monk, who got a DWI 9 weeks ago. Since the " crime" happened over 2 months ago and Detective Sipowicz doesn't really need to do any "investigating", this is no crime episode.