Quite a lot of questionable decisions in both series. Williams isn't playing enough, especially late. I don't like the substitutions. White and Brogdan are both good, but less good together. The slow-down game when they have a lead has led to real issues. Celtics run clock and Young and now Harden make clutch 3s. The other issue is attacking a defense designed to double penetration, leading to turnovers. Kick the ball out and take the open 3s. Stop driving into traffic and expecting a foul call late in the game. There were probably a few that could have been called last night, but that's the playoffs.
Side note: Philly gets away with so many offensive fouls. Harden constantly pushing off is really pretty absurd and they set about 20+ moving screens for him last night, none of which was called.