Even though Chapman had 22 straight saves or whatever since May, he has not been as sharp or effective in many games. Watching that 9th unravel my first thought was - oh you got that game WS win for the Cubs BUT only after you had blown the save. Maybe the arm is catching up and he's effectiveness is limited. Not every Closer can be Mariano - there is only one & he has retired as the best.
As for bringing in another pitcher before the tying run scored - DRob, Zac & Dellin had already done their jobs - there is no longer Chasen Shreve nor Adam Warren. We were watching the league catch up to Holder or maybe he's just going through a midseason funk - did you notice that Sonny Gray would have been the next reliefer