Omi, Kimiko, and Clay were each going through very different stages of grief about the betrayal
They're all ultimately just deeply hurt by what Raimundo did to them, but you can really see the differences in their personality in how they react to pain and rationalize personal tragedy
He's just so naïve and trusting at this point, he can't bring himself to believe that someone he thought cared about them would really decide to purpose trick and hurt them like this. Omi literally can't rationalize it
Before all this, Omi especially looked up to Raimundo and gave him unconditional trust. So Omi would sooner accept any other explanation. Omi was so desperate to see any good here and give his friend the benefit of the doubt that he's just actively deluding himself and denying reality
Omi directly acknowledges how he thinks of his friend Raimundo as cunning and clever and so prone to jokes that Omi doesn't always understand, so surely this was yet another clever, cunning elaborate secret trick that Omi just doesn't understand yet
She's the one who's got the most grounded read on the situation. She's furious that this is happening, but it is happening, and she's not going to take it lying down. She's savvy and intelligent, and she's most ready to try to face it head on
She's even trying to drill the reality of the situation into Omi's head and trying to motivate Clay back into action. Omi and Clay are both avoiding actually doing anything, but Kimiko's more than ready to take charge and fight for this
It's notable that Kimiko's reaction to crisis is the only one that's immediately actionable. They likely would have just piddled around if it weren't for Kimiko more-or-less taking charge here
He's completely shut down, and his usually steady hands are so shaky that he accidentally beheads his little statue while he's trying to whittle. Because trying to suppress, hide, or downplay his own emotions for others is already what Clay tries to do.
He has a whole pile of failed whittling because he's been trembling with emotion for so long. Whittled statues of himself, no less, even though he usually whittles things like cows. Statues of himself he keeps accidentally beheading over and over again, dark...
He's trying to keep himself grounded, but ends up moreso externalizing the pain he wants to suppress
Besides all the trembling from his sadness, he's probably putting too much pressure at certain times from an anger he's trying to suppress, hence all the accidentally broken figurines. He probably nicked himself on the fingers at least once in the process of all those failed figurines
The reason Clay is so visibly shaken up is probably because this is the second time in his life this has happened to him, when we consider his sister. Poor guy's definitely reliving some of the most emotionally taxing moments of his life so far. He and Jesse probably had some sort of argument and exchanged harsh words when she left, but Raimundo's taken it even farther than she ever did
(Which leaves either Jack or Dojo for bargaining?)