The FG% looks bad, but someone had to take shots for them today. I don't know what was wrong with Klay, but he was invisible most of the game. And with Curry being hampered by his ankle and Lee only being able to play a few minutes in short spurts, they needed Barnes and Jack to step-up, which they did.
Barnes missed some good looks and I thought he got fouled a few times but the refs didn't call anything. But it's the playoffs and the refs are going to let more contact go. He had one spurt at the end of the first quarter, after the Warriors had gone forever without a bucket, where he scored something like 6 or 8 straight points to keep them afloat. Then he hit a few big shots in the 4th and OT. He's been really impressive in the playoffs.