Looks like the final play was a hodgepodge of miscommunication between everyone but Tacko. Did Stevens get way too cute putting in Tacko and going to that modified zone, which isn't a defense the Celtics play very often? Should he just have stuck with his starters playing man and not defended the inbounds? I sure think so.
What's sad is I see a lot of bloggers putting this exclusively on Jaylen Brown and it's pretty clear from watching the replay that the whole dysfunction started with poor communication between Smart and Tatum that allowed Anunoby to go completely unchecked along the baseline to the opposite side and then more miscommunication between Jaylen and Theis on who had Gasol leading to Brown being out of position on Anunoby. Though, IMO, Anunoby should have been covered by Tatum who shouldn't have passed him off to double Lowry with Smart. To me it was a team wide breakdown in communication which was precipitated by playing a bad initial zone defense that the players just don't play very often.
As I said earlier in the thread, I got to put the blame on Stevens here. That defense did not put his players in the best position to win that game.