The name of this episode is a reference to the novel Black Sunday about a terrorist attack during a Superbowl game, which was inspired by the true events of the 1972 Olympic games in Munich Germany.
This was the last episode before ABC decided to pull the show, before bringing it back during the summer of 2003.
The Season 8 episode "Blecch Sunday" was the last one of the series that would air during the then-standard Nielsen seasons that began in mid-to-late September of one calendar year and ended in mid-to-late May of the next year. The 12 episode from S8 after "Blecch Sunday" all aired in the summer of 2003; when ABC was unable to cancel the show before its 9th season, the network decided to simply air all of the Season 9 episodes between early June and early September 2004 in order to be done with the series.