Well, I thought at the time the momentum had already shifted to the Astros because their bullpen was so effective.
Nevertheless, it was still a tie game, plus he had planned all along to use Eovaldi because last night was midway between Eovaldi's last start, last Saturday, and presumed next start, this Friday. That move, which made sense, turned sour when Eovaldi foolishly threw four straight fastballs to Correa, who led off the 9th with a double. Right guy, right inning, dumb pitching. When he mixed in breaking balls, he got two K's, but then came that single--after those presumed strikes were called balls--off a splitter a little up in the zone.
You want to make this game outcome all about what you think are Cora's mistakes, but I'm certain the real problem was that the Astros bullpen dominated the Sox lineup. If the Sox ain't hitting this postseason, they ain't winning. Cora in fact used his best arms last night--Pivetta, Taylor, Ottavino, Whitlock, and Eovaldi--until the Sox were down 3-2 in the 9th.