Sabonis missing 50% of his free-throw didn't help. A couple of them are crucial. However, Barnes and Huerter made their free-throw when it matter.
What an odd odd argument for you to make. Did Domas miss some free throws? Yes. And do we generally need to do better at free throws as a team? Yes. But were his misses clutch free throws that turned the game around? No. In fact, the last two free throws Domas missed were at the 9 minute mark, with us trailing by two points. We got a stop (Domas the board) and then Monk hit two free throws to tie it up. So really no harm no foul.
To claim otherwise is to basically make the foolish Grant Napear argument that every missed free throw should just be added to our final score as though the game would have unfolded the exact same way if he had made them. It doesn't work that way. The game would have unfolded differently because the different score would have led to different in game decisions and realities. Missed free throws early in the game only really hurt if they are compounded in a way that changes momentum. That didn't happen here since we got the stop and got the points back the next possession.
Missed free throws late in games, on the other hand, are critical, and can have a profound impact on the final score since there is so little time to recover from them. You are correct to positively note that Barnes and Huerter hit huge free throws. Huerter hit two free throws at the 3:11 mark to bring us to down 1. Barnes hit 2 at the 2:53 mark to give us a 1 point lead. Just massive free throws. But that bum Domas, whose free throws were apparently our undoing, gets no credit for hitting two at the 1:12 mark to give us a 3 point lead. Massive free throws as well.
Finally, since the NBA likes to use the 5:00 minute mark to define clutch time, Domas was 3-3 FG, 2-2 FT, (8 points and 1 assist) in the last 5 minutes. Perfect shooting and directly responsible for 10 of our 16 points. He also made the pass that set up the two Huerter free throws, and had a hockey assist on the Monk layup that was assisted by Keegan.